libpayload: sync ARMv7 arch/io.h with coreboot

On ARMv7 we need to carefully add memory barriers to
all memory read and write operations. This change
brings libpayload in sync with what coreboot is doing.

Signed-off-by: Stefan Reinauer <reinauer@google.com>

Change-Id: Ie9c30b0f0d30531c5f9d99c2729246a86b8cec26
Reviewed-on: https://gerrit.chromium.org/gerrit/59294
Reviewed-by: Gabe Black <gabeblack@chromium.org>
Tested-by: Stefan Reinauer <reinauer@chromium.org>
Commit-Queue: Stefan Reinauer <reinauer@chromium.org>
Reviewed-on: http://review.coreboot.org/4316
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
1 file changed