arm: ep93xx: use DEFINE_RES_* macros

Use the DEFINE_RES_* macros to reduce some of the boilerplate code.

Signed-off-by: Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Mika Westerberg <mika.westerberg@iki.fi>
Signed-off-by: Ryan Mallon <rmallon@gmail.com>