[IA64] Fix virtualized EFI memory mapping creation for dom0.

[IA64] Fix virtualized EFI memory mapping creation for dom0.

EFI uses 4k page, while xen uses 16k page.  For dom0, identity mappings
are setup for EFI_ACPI_RECLAIM_MEMORY etc.  It is possible when seting
up dom0 memory ranges to include some EFI_ACPI_RECLAIM_MEMORY ranges
due to 4k/16k alignment difference.

This patch fixes this issue by scaning memory descriptors twice.  In the
first scan, setup dom0 identity mapping.  In the second scan, setup
dom0 memory mapping.

Signed-off-by: Anthony Xu <anthony.xu@intel.com>