[doc] Update references to util/vendor.py tool.

As part of lowrisc/opentitan#607, rename references from `vendor_hw` to
`util/vendor`. Also, rename `doc/rm/vendor_hw_tool.md` as
`doc/rm/vendor_in_tool.md`.

Signed-off-by: Miguel Osorio <miguelosorio@google.com>
diff --git a/doc/rm/_index.md b/doc/rm/_index.md
index e8dc25a..4deb30d 100644
--- a/doc/rm/_index.md
+++ b/doc/rm/_index.md
@@ -5,7 +5,7 @@
    * [Topgen Tool]({{< relref "topgen_tool" >}}): Describes `topgen.py` and its Hjson format source. Used to generate rtl and validation files for top specific modules such as PLIC, Pinmux and crossbar.
    * [Register Tool]({{< relref "register_tool" >}}): Describes `regtool.py` and its Hjson format source. Used to generate documentation, rtl, header files and validation files for IP Registers and toplevel.
    * [Crossbar Tool]({{< relref "crossbar_tool" >}}): Describes `tlgen.py` and its Hjson format source. Used to generate self-documentation, rtl files of the crossbars at the toplevel.
-   * [Vendor-In Tool]({{< relref "vendor_hw_tool" >}}): Describes `vendor_hw.py` and its Hjson control file. Used to pull a local copy of code maintained in other upstream repositories and apply local patch sets.
+   * [Vendor-In Tool]({{< relref "vendor_in_tool" >}}): Describes `util/vendor.py` and its Hjson control file. Used to pull a local copy of code maintained in other upstream repositories and apply local patch sets.
 * Coding Style Guides
   * [Verilog Coding Style](https://github.com/lowRISC/style-guides/blob/master/VerilogCodingStyle.md)
   * [Python Coding Style]({{< relref "python_coding_style.md" >}})
diff --git a/doc/rm/vendor_hw_tool.md b/doc/rm/vendor_in_tool.md
similarity index 76%
rename from doc/rm/vendor_hw_tool.md
rename to doc/rm/vendor_in_tool.md
index a8b0746..d33f0fb 100644
--- a/doc/rm/vendor_hw_tool.md
+++ b/doc/rm/vendor_in_tool.md
@@ -1,19 +1,19 @@
 ---
-title: "vendor_hw: vendor-in hardware components"
+title: "util/vendor.py: Vendor-in Components"
 ---
 
-Not all hardware code contained in this repository is actually developed within this repository.
-Code which we include from external sources is placed in the `hw/vendor` directory and copied into this directory from its upstream source.
-The process of copying the upstream sources is called vendoring, and it is automated by the `vendor_hw` tool.
+Not all code contained in this repository is actually developed within this repository.
+Code which we include from external sources is placed in `vendor` sub-directories (e.g. `hw/vendor`) and copied over from upstream sources.
+The process of copying the upstream sources is called vendoring, and it is automated by the `util/vendor` tool.
 
-The `vendor_hw` tool can go beyond simply copying in source files: it can patch them, it can export patches from commits in a Git repository, and it can commit the resulting changes with a meaningful commit message.
+The `util/vendor` tool can go beyond simply copying in source files: it can patch them, it can export patches from commits in a Git repository, and it can commit the resulting changes with a meaningful commit message.
 
 ## Tool usage overview
 
 ```text
-usage: vendor_hw [-h] [--refresh-patches] [--commit] [--verbose] file
+usage: vendor [-h] [--refresh-patches] [--commit] [--verbose] file
 
-vendor_hw, copy hardware source code from upstream into this repository
+vendor, copy source code from upstream into this repository
 
 positional arguments:
   file               vendoring description file (*.vendor.hjson)
@@ -27,8 +27,8 @@
 
 ## The vendor description file
 
-For each vendored-in component a description file must be created, which serves as input to the `vendor_hw` tool.
-The vendor description file is stored in `hw/vendor/<vendor>_<name>.vendor.hjson`.
+For each vendored-in component a description file must be created, which serves as input to the `util/vendor` tool.
+The vendor description file is stored in `vendor/<vendor>_<name>.vendor.hjson`.
 By convention all imported code is named `<vendor>_<name>`, with `<vendor>` typically being the GitHub user or organization name, and `<name>` the project name.
 It is recommended to use only lower-case characters.
 
@@ -61,7 +61,7 @@
   patch_dir: "patches/pulp_riscv_dbg",
 
   // Optional: Update patches in |patch_dir| from a Git repository
-  // If vendor_hw is run with --refresh-patches, all commits in the repository
+  // If util/vendor is run with --refresh-patches, all commits in the repository
   // at |url| between |rev_base| and |rev_patched| are exported into the
   // |patch_dir|, replacing all existing patches.
   patch_repo: {
@@ -105,5 +105,5 @@
 ### Update code and commit the new code
 ```command
 $ cd $REPO_TOP
-$ ./util/vendor_hw.py hw/vendor/google_riscv-dv.vendor.hjson -v --commit
+$ ./util/vendor.py hw/vendor/google_riscv-dv.vendor.hjson -v --commit
 ```