gpio/omap: handle set_dataout reg capable IP on restore

GPIO IP revisions such as those used in OMAP4 have a set_dataout
while the previous revisions used a single dataout register.
Depending on what is available restore the dataout settings
to the right register.

Signed-off-by: Nishanth Menon <nm@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>