MdeModulePkg S3SaveStateDxe: Move S3Ready() functional code from AcpiS3SaveDxe

MdeModulePkg S3SaveStateDxe: Move S3Ready() functional code from AcpiS3SaveDxe

The S3Ready() functional code in AcpiS3SaveDxe of IntelFrameworkModulePkg
is to do ACPI S3 Context save. In fact, that is not really related to
Intel framework ACPI S3 protocol.

IntelFrameworkModulePkg will be deprecated step by step, so move the
functional code to MdeModulePkg and S3SaveStateDxe is a good place.
The ACPI global variable related code is leaved as is in IntelFrameworkModulePkg
AcpiS3SaveDxe for compatibility.
PcdS3BootScriptStackSize is also moved from IntelFrameworkModulePkg.

The functional code need to get ACPI FACS table and consume LockBoxLib,
so need to be before DxeSmmReadyToLock that will shut down SMM lock box
interface, EndOfDxe is a good point (OVMF AcpiS3SaveDxe has the reference
implementation).

Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Feng Tian <feng.tian@intel.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>