GPIOs should be requested before use. Without this, driver model will
not permit the GPIO to be used.

Cc: Igor Grinberg <grinberg@compulab.co.il>
Signed-off-by: NSimon Glass <sjg@chromium.org>
Signed-off-by: NNikita Kiryanov <nikita@compulab.co.il>
Acked-by: NIgor Grinberg <grinberg@compulab.co.il>