imx35-regs: add and use common CGR element shifters
Add some missing Clock Gate Register element shifters which were implemented
as magic numbers in the arm/boards directory. Use the new shifters for
inproved code readability.
Signed-off-by: Alexander Kurz <akurz@blala.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>