efi: create memory map iteration helper

There are a lot of places in the kernel which iterate through an
EFI memory map. Most of these places use essentially the same
for-loop code. This patch adds a for_each_efi_memory_desc()
helper to clean up all of the existing duplicate code and avoid
more in the future.

Signed-off-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Git-commit: e885cd805fc6e65ef5150a211c7bac02f925af04
Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org>