soc: ti: omap-prm: am3: add genpd support for remaining PRM instances

Add genpd support for per, wkup, mpu, rtc and cefuse instances.

Cc: Santosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>