ARM: OMAP2/3: clockdomain/PRM/CM: move the low-level clockdomain functions into PRM/CM

ARM: OMAP2/3: clockdomain/PRM/CM: move the low-level clockdomain functions into PRM/CM

Move the low-level SoC-specific clockdomain control functions into
cm*.c and prm*.c.  For example, OMAP2xxx low-level clockdomain
functions go into cm2xxx.c.  Then remove the unnecessary
clockdomain*xxx*.c files.

The objective is to centralize low-level CM and PRM register accesses
into the cm*.[ch] and prm*.[ch] files, and then to export an OMAP
SoC-independent API to higher-level OMAP power management code.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Rajendra Nayak <rnayak@ti.com>
Cc: Vaibhav Hiremath <hvaibhav@ti.com>
Acked-by: Rajendra Nayak <rnayak@ti.com>
Reviewed-by: Russ Dill <Russ.Dill@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>