AcpiS3Save could try to check PcdIdentifyMappingPageTablePtr is NULL, if it is not, it means someone else has allocate memory for page table, AcpiS3Save could re-use this memory.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Elvin Li <elvin.li@intel.com>
Signed-off-by: Jiewen Yao <jiewen.yao@intel.com>

git-svn-id: svn://svn.code.sf.net/p/edk2/code/trunk/edk2/IntelFrameworkModulePkg@15910 6f19259b-4bc3-4df7-8a09-765794883524