MdeModulePkg: Add S3SmmInitDone definition

MdeModulePkg: Add S3SmmInitDone definition

Add gEdkiiS3SmmInitDoneGuid, after S3 SMM initialization is done and
before S3 boot script is executed, this GUID is installed as PPI in
PEI and protocol in SMM environment. It allows for PEIMs or SMM
drivers to hook this point and do the required tasks.

Cc: Jiewen Yao <jiewen.yao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>