Add support for building code for Debian armhf

I think this will work with the Ubuntu-based distribution on the TK1
too.

Change-Id: I62350d2f7a8914fb13c421be427388c6e46c5481
diff --git a/tools/BUILD b/tools/BUILD
index 22ce501..59cf695 100644
--- a/tools/BUILD
+++ b/tools/BUILD
@@ -20,6 +20,10 @@
   values = {'cpu': 'roborio'},
 )
 config_setting(
+  name = 'cpu_armhf',
+  values = {'cpu': 'armhf-debian'},
+)
+config_setting(
   name = 'has_asan',
   values = {'copt': '-fsanitize=address'},
 )
@@ -27,3 +31,7 @@
   name = 'has_tsan',
   values = {'copt': '-fsanitize=thread'},
 )
+config_setting(
+  name = 'has_ubsan',
+  values = {'copt': '-fsanitize=undefined'},
+)