1. Support get default value for ref opcode logic.
2. Correct the sample for ref opcode with default value.
3. Refine logic about processing device path info in ref value.
Signed-off-by: ydong10
Reviewed-by: lgao4
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@12774 6f19259b-4bc3-4df7-8a09-765794883524