OMAP4: PM: work around for CPU1 onlining from OFF/OSWR state on older PPA

Originally detected in OMAP4430 ES2.3 HS samples, CPU1 crashes the
device upon calling PPA service DEFAULT_POR_NS_SMP(0x25).

Rootcause showed that cache maintenance operations required to be
performed before handing over control of CPU1 to HLOS, were incomplete
and not broadcasted from CPU0 to CPU1.

Kernel workaround for this is to use WFI to put CPU1 in OFF
state if CPU0 is not ready yet (this mechanism was in place in previous
versions of this code base but was meant to address a different need).
When putting CPU1 back to off, its internal MMU descriptors are reset
and sync'd with CPU0. CPU1 is brought online by later kernel subsystems.
Note: CPU0 power state is made to OFF for both OSWR and OFF modes.

This issue has been analysed to impact all OMAP4 non GP devices.

A config flag is introduced to allow platforms and distributions to
enable/disable if PPA version requirement is not met.

Change-Id: I82c5880ec2d9a98a54755dfbd01aa981cfed9852
[nm@ti.com, cileija@ti.com: improvements and rootcause support]
Signed-off-by: Carlos Leija <cileija@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com]
[wwang@ti.com: WA identification]
Signed-off-by: Wenbiao Wang <wwang@ti.com>

Conflicts:

	arch/arm/mach-omap2/Kconfig

Conflicts:

	arch/arm/mach-omap2/Kconfig