libpayload: also support armv7-a toolchain

Change-Id: I9b80b72de96fb28489dcc8547b8f748ea4fcc355
Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Reviewed-on: http://review.coreboot.org/7074
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Tested-by: Patrick Georgi <pgeorgi@google.com>
1 file changed