build: everyone gets verilator!

Having verilator installed only for certain platforms can cause confusion;
install it regardless of the current platform setting.

Change-Id: I459b6cfb6331f7eb5a6d49843ca45e8274f7ee30

Makefile

diff --git a/Makefile b/Makefile
index 56bca1a..4babc53 100644
--- a/Makefile
+++ b/Makefile
@@ -59,7 +59,7 @@
 # This includes Rust, GCC, CLANG, verilator, and renode.
 #
 # Output is placed in cache/ and out/host.
-tools:: install_rust install_gcc install_llvm install_kelvin renode
+tools:: install_rust install_gcc install_llvm install_kelvin renode verilator
 
 ## Cleans the entire system
 #

platforms/nexus/platform.mk

diff --git a/platforms/nexus/platform.mk b/platforms/nexus/platform.mk
index 48e93be..f4818ba 100644
--- a/platforms/nexus/platform.mk
+++ b/platforms/nexus/platform.mk
@@ -90,6 +90,3 @@
 	rm -f $(TIMER_HJSON)
 	rm -f $(TIMER_HEADER)
 	rm -f $(TOP_MATCHA_IRQ_HEADER) $(TOP_MATCHA_MEMORY_HEADER)
-
-# Ensure we build verilator as part of tools for this platform
-tools:: verilator

platforms/shodan/platform.mk

diff --git a/platforms/shodan/platform.mk b/platforms/shodan/platform.mk
index 5e898da..02fdec9 100644
--- a/platforms/shodan/platform.mk
+++ b/platforms/shodan/platform.mk
@@ -95,6 +95,3 @@
 	rm -f $(TIMER_HJSON)
 	rm -f $(TIMER_HEADER)
 	rm -f ${TOP_MATCHA_IRQ_HEADER} ${TOP_MATCHA_MEMORY_HEADER}
-
-# Ensure we build verilator as part of the tools for this platform
-tools:: verilator

platforms/sparrow/platform.mk

diff --git a/platforms/sparrow/platform.mk b/platforms/sparrow/platform.mk
index ef3521a..1ecc02c 100644
--- a/platforms/sparrow/platform.mk
+++ b/platforms/sparrow/platform.mk
@@ -90,6 +90,3 @@
 	rm -f $(TIMER_HJSON)
 	rm -f $(TIMER_HEADER)
 	rm -f $(TOP_MATCHA_IRQ_HEADER) $(TOP_MATCHA_MEMORY_HEADER)
-
-# Ensure we build verilator as part of tools for this platform
-tools:: verilator