[dv/top] Remove ImplGeneric default assignment

This is not needed since all prims default to the generic
implementation. Also, it can collide with technology specific simulation
configs in the closed source foundry repo.

Signed-off-by: Michael Schaffner <msf@google.com>
diff --git a/hw/top_earlgrey/dv/chip_sim_cfg.hjson b/hw/top_earlgrey/dv/chip_sim_cfg.hjson
index 502828d..a0f28e1 100644
--- a/hw/top_earlgrey/dv/chip_sim_cfg.hjson
+++ b/hw/top_earlgrey/dv/chip_sim_cfg.hjson
@@ -84,10 +84,6 @@
   uvm_test_seq: chip_sw_base_vseq
   sw_build_device: sim_dv
 
-  // Add default build_opts.
-  build_opts: [// Use generic implementations of prim modules.
-               "+define+PRIM_DEFAULT_IMPL=prim_pkg::ImplGeneric"]
-
   // Add build modes.
   build_modes: [
     {
diff --git a/hw/top_earlgrey/top_earlgrey.core b/hw/top_earlgrey/top_earlgrey.core
index 41ea14e..d9fb178 100644
--- a/hw/top_earlgrey/top_earlgrey.core
+++ b/hw/top_earlgrey/top_earlgrey.core
@@ -81,13 +81,6 @@
   SYNTHESIS:
     datatype: bool
     paramtype: vlogdefine
-  # For value definition, please see ip/prim/rtl/prim_pkg.sv
-  PRIM_DEFAULT_IMPL:
-    datatype: str
-    paramtype: vlogdefine
-    description: Primitives implementation to use, e.g. "prim_pkg::ImplGeneric".
-    default: prim_pkg::ImplGeneric
-
 
 targets:
   default: &default_target
@@ -96,16 +89,12 @@
       - tool_ascentlint  ? (files_ascentlint_waiver)
       - tool_veriblelint ? (files_veriblelint_waiver)
       - files_rtl_generic
-    parameters:
-      - PRIM_DEFAULT_IMPL=prim_pkg::ImplGeneric
     toplevel: top_earlgrey
 
   sim:
     default_tool: icarus
     filesets:
       - files_rtl_generic
-    parameters:
-      - PRIM_DEFAULT_IMPL=prim_pkg::ImplGeneric
     toplevel: top_earlgrey
 
   lint:
diff --git a/hw/top_earlgrey/top_earlgrey_asic.core b/hw/top_earlgrey/top_earlgrey_asic.core
index a6b5b4a..11df4da 100644
--- a/hw/top_earlgrey/top_earlgrey_asic.core
+++ b/hw/top_earlgrey/top_earlgrey_asic.core
@@ -47,8 +47,6 @@
       - tool_ascentlint  ? (files_ascentlint_waiver)
       - tool_veriblelint ? (files_veriblelint_waiver)
       - files_rtl
-    parameters:
-      - PRIM_DEFAULT_IMPL=prim_pkg::ImplGeneric
     toplevel: top_earlgrey_asic
 
   lint: