This patch makes the {read,write}_reg functions const, this is a preparation to
make use of {read,write}_reg in the hwinit callback.
Signed-off-by: NThor Thayer <tthayer@altera.com>
Signed-off-by: NPavel Machek <pavel@denx.de>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>