printk: support and use %hh prefix

clang complains otherwise.

Change-Id: I2ac98d7147ecd3d7064f17f8c9d214d44baedf97
Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Reviewed-on: http://review.coreboot.org/4717
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
2 files changed