efi: Add support for EFI_MEMORY_RO attribute introduced by UEFIv2.5

efi: Add support for EFI_MEMORY_RO attribute introduced by UEFIv2.5

The UEFI spec v2.5 introduces a new memory attribute
EFI_MEMORY_RO, which is now the preferred attribute to convey
that the nature of the contents of such a region allows it to be
mapped read-only (i.e., it contains .text and .rodata only).

The specification of the existing EFI_MEMORY_WP attribute has been
updated to align more closely with its common use as a
cacheability attribute rather than a permission attribute.

Add the #define and add the attribute to the memory map dumping
routine.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1438936621-5215-1-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>