iommu/vt-d: Check VT-d RMRR region in BIOS is reported as reserved

VT-d RMRR (Reserved Memory Region Reporting) regions are reserved
for device use only and should not be part of allocable memory pool of OS.

BIOS e820_table reports complete memory map to OS, including OS usable
memory ranges and BIOS reserved memory ranges etc.

x86 BIOS may not be trusted to include RMRR regions as reserved type
of memory in its e820 memory map, hence validate every RMRR entry
with the e820 memory map to make sure the RMRR regions will not be
used by OS for any other purposes.

ia64 EFI is working fine so implement RMRR validation as a dummy function

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Sohil Mehta <sohil.mehta@intel.com>
Signed-off-by: Yian Chen <yian.chen@intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>