Fixing yang_model macro to narrow down the dependency list.

Change-Id: I6ae11cec370bfca4a1e4fe0598f84c7e354ea5b8
diff --git a/tools/dev/bin/patch-yang-libs b/tools/dev/bin/patch-yang-libs
index 6e56ccc..d6ab3ea 100755
--- a/tools/dev/bin/patch-yang-libs
+++ b/tools/dev/bin/patch-yang-libs
@@ -3,7 +3,7 @@
 # Patches lib/BUCK file to use locally built YANG tools.
 # -----------------------------------------------------------------------------
 
-BVER=1.12.0-b6
+BVER=1.12.0-b7
 SVER=1.12-SNAPSHOT
 
 YANG_TOOLS_ROOT=~/onos-yang-tools