Upgrade FuseSoC command

FuseSoC commands `sim` and `build` are deprecated, use `run` instead.
https://github.com/olofk/fusesoc/commit/b838e89e5093aa0c87620314e95d319a87b64b24
diff --git a/hw/formal/rtl_diff b/hw/formal/rtl_diff
index c669aa4..6989f3b 100755
--- a/hw/formal/rtl_diff
+++ b/hw/formal/rtl_diff
@@ -19,7 +19,7 @@
 # use fusesoc to generate file list
 #-------------------------------------------------------------------------
 \rm -Rf build rtl_diff.log
-fusesoc --cores-root .. sim --build-only formal > /dev/null 2>&1
+fusesoc --cores-root .. run --target=sim --setup --build formal > /dev/null 2>&1
 
 #-------------------------------------------------------------------------
 # run Conformal LEC