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/Makefile b/arch/arm/mach-omap2/Makefile
index 3b5d184..d543896 100644
--- a/arch/arm/mach-omap2/Makefile
+++ b/arch/arm/mach-omap2/Makefile
@@ -3,7 +3,7 @@
 #
 
 # Common support
-obj-y := id.o io.o control.o mux.o devices.o serial.o gpmc.o timer-gp.o
+obj-y := id.o io.o control.o mux.o devices.o serial.o gpmc.o timer-gp.o pm.o
 
 omap-2-3-common				= irq.o sdrc.o
 hwmod-common				= omap_hwmod.o \