MdeModulePkg/PiSmmCore: MemoryAttributeTable need keep non-PE record.

MdeModulePkg/PiSmmCore: MemoryAttributeTable need keep non-PE record.

Current memory attribute table implementation will only mark PE code
to be EfiRuntimeServicesCode, and mark rest to be EfiRuntimeServicesData.

However, there might be a case that a SMM code wants to allocate
EfiRuntimeServicesCode explicitly to let page table protect this region
to be read only. It is unsupported.

This patch enhances the current solution so that MemoryAttributeTable
does not touch non PE image record.
Only the PE image region is forced to be EfiRuntimeServicesCode for
code and EfiRuntimeServicesData for data.

Cc: Jeff Fan <jeff.fan@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Jeff Fan <jeff.fan@intel.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>