libpayload: arm(64): add read8/16/32 and write8/16/32

libpayload: arm(64): add read8/16/32 and write8/16/32

This applys the same change made by
https://chromium-review.googlesource.com/261692
to libpayload.

BUG=none
BRANCH=tot
TEST=built for veyron_jerry, rush_ryu, samus

Change-Id: I26dd66d79cd1559a7852b3c9d252420f2fed5fa0
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: d0d6f70aa805e18966e80618fbf9e9605274b030
Original-Change-Id: Ib0c199238f8fa58643d51782b17550dbd0d9ebd7
Original-Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/282541
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/10773
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>