MdePkg, MdeModulePkg: S3BootScriptSaveMemPoll(): accept 64-bit LoopTimes

MdePkg, MdeModulePkg: S3BootScriptSaveMemPoll(): accept 64-bit LoopTimes

The BaseNull instance of S3BootScriptLib obviously doesn't care about the
type of the S3BootScriptSaveMemPoll() function's LoopTimes parameter; this
lib instance doesn't do anything with the parameters received in
S3BootScriptSaveMemPoll().

The PiDxe instance saves the LoopTimes parameter in
EFI_BOOT_SCRIPT_MEM_POLL.LoopTimes. This target field already has UINT64
type. Furthermore, the BootScriptExecuteMemPoll() function in the same
library instance already uses a local UINT64 variable called LoopTimes to
count up to EFI_BOOT_SCRIPT_MEM_POLL.LoopTimes. This means that the the
UINTN type for S3BootScriptSaveMemPoll()'s LoopTimes parameter is an
unnecessary restriction.

The callers of S3BootScriptSaveMemPoll() will be updated in the next
patches, functionally. At this stage, they will continue to compile, since
UINT64 parameters can accept UINTN arguments.

Cc: Feng Tian <feng.tian@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: "Yao, Jiewen" <jiewen.yao@intel.com>
Reviewed-by: Michael Kinney <michael.d.kinney@intel.com>