MdeModulePkg/PiDxeS3BootScriptLib: Rename mAcpiS3Enable to avoid dup symbol

MdeModulePkg/PiDxeS3BootScriptLib: Rename mAcpiS3Enable to avoid dup symbol

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3297

Rename the global variable mAcpiS3Enable to mS3BootScriptAcpiS3Enable
to avoid duplicate symbol errors from CLANGPDB tool change when
PiDxeS3BootScriptLib from the MdeModulePkg is linked with PiSmmCpuDxeSmm
from the UefiCpuPkg.

Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao A Wu <hao.a.wu@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Hao A Wu <hao.a.wu@intel.com>