Disable LLVM_MAIN_REVISION update in post-merge hook

   - LLVM_MAIN_REVISION update in post-merge hook causes
     divergence in development workspace
   - Combination like git reset + git pull + git pull causes
     issues
   - This temporay patch makes post-merge hook a no-op

Change-Id: Ic0f89da06301ad9eae0234d39a0dc8d319b2fa60

Author: skganesan008

amd/git-hooks/llvm-main-revision

@@ -16,6 +16,9 @@ if test "$ACTION_TYPE" = "pre-commit"; then
   fi
 fi
 
+#disable automatic llvm-config.h.cmake LLVM_MAIN_REVISION update
+exit 0
+
 LLVM_CONFIG_H_CMAKE_PATH="llvm/include/llvm/Config/llvm-config.h.cmake"
 
 FETCH_HASH=$(git log --oneline --format='%h' --max-count=1 FETCH_HEAD)