[ARM] OMAP2/3 clockdomains: add CM and PRM clkdms

Add clockdomains for the CM and PRM.  These will ultimately replace the
"wkup_clkdm", which appears to not actually exist on the hardware.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>