Add //tools:armhf-debian to the default environment group

Everything builds for the Jetson anyways, so let's just stick to it.
More compilers aren't a bad thing.  This will prevent more of the code
base from needing to be annotated.

Change-Id: I501b384c8073e245f11f0e0c3e5f9b494ad89a66
diff --git a/tools/BUILD b/tools/BUILD
index 3a75af3..6993e5f 100644
--- a/tools/BUILD
+++ b/tools/BUILD
@@ -68,6 +68,7 @@
     defaults = [
         ":k8",
         ":roborio",
+        ":armhf-debian",
     ],
     environments = [
         ":k8",