OMAP: PM: create omap_devices for MPU, DSP, L3

Create simple omap_devices for the main processors and busses.

This is required to support the forth-coming device-based OPP
approach, where OPPs are managed and tracked at the device level.

Also, move these common PM init functions into a common_pm_init call
that is called as a device_initcall().  The PM init is done at this level
to ensure that the driver core is initialized before initialized.

Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
[paul@pwsan.com: sparse warnings cleaned up; newly-created functions moved
 from mach-omap2/io.c to mach-omap2/pm.c; newly-created functions renamed
 to start with "omap2" rather than "omap"]
Signed-off-by: Paul Walmsley <paul@pwsan.com>
diff --git a/arch/arm/mach-omap2/io.c b/arch/arm/mach-omap2/io.c
index e95b47b..d1906c7 100644
--- a/arch/arm/mach-omap2/io.c
+++ b/arch/arm/mach-omap2/io.c
@@ -45,6 +45,7 @@
 
 #include <plat/clockdomain.h>
 #include "clockdomains.h"
+
 #include <plat/omap_hwmod.h>
 
 /*
@@ -349,7 +350,6 @@
 	if (cpu_is_omap24xx() || cpu_is_omap34xx())   /* FIXME: OMAP4 */
 		omap_hwmod_late_init(skip_setup_idle);
 
-	omap_pm_if_init();
 	if (cpu_is_omap24xx() || cpu_is_omap34xx()) {
 		omap2_sdrc_init(sdrc_cs0, sdrc_cs1);
 		_omap2_init_reprogram_sdrc();