UefiCpuPkg/PiSmmCpu: Correct exception message.

UefiCpuPkg/PiSmmCpu: Correct exception message.

This patch fixes the first part of
https://bugzilla.tianocore.org/show_bug.cgi?id=242

Previously, when SMM exception happens, "stack overflow" is misreported.
This patch checked the PF address to see it is stack overflow, or
it is caused by SMM page protection.

It dumps exception data, PF address and the module trigger the issue.

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