arch/x86: Do not access EFI memory map if it is not available
arch/x86: Do not access EFI memory map if it is not available

Do not access EFI memory map if it is not available. At least
Xen dom0 EFI implementation does not have an access to it.

Signed-off-by: Daniel Kiper <dc8d375c69cae8f3beab0c5cd589b0c6b194d0db@oracle.com>
Signed-off-by: Matt Fleming <b02f0790d66a0f0a6b369873bf6df37420fbe5dd@intel.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs