gpio: mxc: Use devm_clk_get_optional instead of devm_clk_get

i.MX SoC's GPIO clock is optional, so it is better to use
devm_clk_get_optional instead of devm_clk_get.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
1 file changed