gpio: max77650: add MODULE_ALIAS()

Define a MODULE_ALIAS() in the gpio sub-driver for max77650 so that
the appropriate module gets loaded together with the core mfd driver.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Link: https://lore.kernel.org/r/20190703084601.9276-1-brgl@bgdev.pl


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>