build: ignoring build residue AM-604/4_0_1

Author: Aaron Roller

.gitignore

@@ -59,4 +59,5 @@ cmake-build-debug
 .history
 am-onboard-sdk-build-deps_*_all.deb
 debian/am-onboard-sdk*
-debian/.debhelper/
+debian/.debhelper/
+debian/rules