ARM: davinci: da8xx-dt: switch to device tree clocks

This removes all of the clock init code from da8xx-dt.c. This includes
all of the OF_DEV_AUXDATA that was just used for looking up clocks.

Signed-off-by: David Lechner <david@lechnology.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>