pinctrl: armada-37xx: Checks for errors in gpio_request_enable callback

pinctrl: armada-37xx: Checks for errors in gpio_request_enable callback

Now when all MPP pins are properly defined and every MPP pin has GPIO
function, always checks for errors in armada_37xx_gpio_request_enable()
function when calling armada_37xx_pmx_set_by_name(). Function
armada_37xx_pmx_set_by_name() should not return "not supported" error
anymore for any GPIO pin when requesting GPIO mode.

Fixes: 87466ccd9401 ("pinctrl: armada-37xx: Add pin controller support for Armada 37xx")
Signed-off-by: Pali Rohár <pali@kernel.org>
Link: https://lore.kernel.org/r/20220805122202.23174-3-pali@kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>