ARM: OMAP2+: PRCM: store also physical addresses for instances

In some cases the physical address info is needed, so store this
under the existing cm*_base, prm_base and prcm_mpu_base variables.
These are converted now to structs that contain both virtual and
physical address base for the instance.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>