ARM: OMAP2+: PRM: determine PRM base address from device tree

There is no need to provide the PRM base address through a low-level API
from the low-level IO init, as this information is available through DT.
Re-routed the parsing function to be called from the PRM drivers also to
simplify the implementation under io.c.

Signed-off-by: Tero Kristo <t-kristo@ti.com>

arch/arm/mach-omap2/prm33xx.c

@@ -380,6 +380,7 @@ static struct prm_ll_data am33xx_prm_ll_data = {
 
 int __init am33xx_prm_init(void)
 {
+	omap2_prm_base_init();
 	return prm_register(&am33xx_prm_ll_data);
 }