Small cleanups preparing for fet12v2 code

Change-Id: I3c0da058c4aef78bd7cc7590824f54ca664bfbae
diff --git a/frc971/control_loops/BUILD b/frc971/control_loops/BUILD
index 16673df..12d3a4b 100644
--- a/frc971/control_loops/BUILD
+++ b/frc971/control_loops/BUILD
@@ -133,7 +133,7 @@
     hdrs = [
         "state_feedback_loop.h",
     ],
-    restricted_to = ["//tools:cortex-m4f"],
+    restricted_to = mcu_cpus,
     deps = [
         "//aos/common:macros",
         "//third_party/eigen",