gpio/omap: fix incorrect context restore logic in omap_gpio_runtime_*

In omap_gpio_runtime_suspend/resume() the context save/restore should
be independent of bank->enabled_non_wakeup_gpios. This was preventing
context restore of GPIO lines which are not wakeup enabled.

Reported-by: Govindraj Raja <govindraj.raja@ti.com>
Signed-off-by: Tarun Kanti DebBarma <tarun.kanti@ti.com>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>