OMAP3 PM: off-mode support for HS/EMU devices

For HS/EMU devices, some additional resources need to be
saved/restored for off-mode support.  Namely, saving the secure RAM
and a pointer to it in the scratchpad.

Signed-off-by: Tero Kristo <tero.kristo@nokia.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>