ARM: omap2+: clockdomain: add clkdm_xlate_address

This new function can be used to get the physical address of a
clockdomain. Required for mapping the clkctrl clocks under hwmod
without modification to DT data.

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