OMAP3630: PM: Erratum i608: disable RTA

Erratum id: i608
RTA (Retention Till Access) feature is not supported and leads to device
stability issues when enabled. This impacts modules with embedded memories
on OMAP3630

Workaround is to disable RTA on boot and coming out of core off.
For disabling RTA coming out of off mode, we do this by overriding the
restore pointer for 3630 as the first point of entry before caches are
touched and is common for GP and HS devices. To disable earlier than
this could be possible by modifying the PPA for HS devices, but not for
GP devices.

Cc: Kevin Hilman <khilman@deeprootsystems.com>
Cc: Tony Lindgren <tony@atomide.com>

Acked-by: Jean Pihet <j-pihet@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>

[ambresh@ti.com: co-developer]
Signed-off-by: Ambresh K <ambresh@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>