Eliminate duplicated file GUID.

Eliminate duplicate GUID definition.
Do explicit data cast.
Use StrnCpy instead of StrCpy.
Update GCC assembly.

Contributed-under: TianoCore Contribution Agreement 1.0

Signed off by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed by: Eric Dong <eric.dong@intel.com>
Reviewed by: Liming Gao <liming.gao@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15762 6f19259b-4bc3-4df7-8a09-765794883524