SecurityPkg-Opal(2): Enhance AHCI Bar MMIO region check.

SecurityPkg-Opal(2): Enhance AHCI Bar MMIO region check.

This patch enhance OPAL password SMM driver to check SMM bar is valid MMIO
besides outside of SMRAM.

This is designed to meet Microsoft WSMT table definition on FIXED_COMM_BUFFERS
requirement.

Cc: Eric Dong <eric.dong@intel.com>
Cc: Feng Tian <feng.tian@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Eric Dong <eric.dong@intel.com>
Reviewed-by: Feng Tian <feng.tian@intel.com>