ARM: OMAP2+: Wakeupgen: AM43xx HS devices should save context like non-HS

Unlike some previous generation devices, AM43xx HS IRQ and Wakegen
context is handled by the ROM for us, and no secure service call
is needed or supported. Non-GP AM43xx devices should take the
same path as GP.

Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>