gpio: omap: handle deferred probe with dev_err_probe() for gpiochip_add_data()

The gpiochip_add_data() may return -EPROBE_DEFER which is not handled
properly by TI GPIO driver and causes unnecessary boot log messages.

Hence, add proper deferred probe handling with new dev_err_probe() API.

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>