MdeModulePkg: Introduce new PCD PcdAcpiS3Enable

MdeModulePkg: Introduce new PCD PcdAcpiS3Enable

Platform can configure the PCD statically or dynamically
to control if ACPI S3 will be enabled.
S3 related modules can consume the PCD to control the code.

Cc: Feng Tian <feng.tian@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>