gpio: altera: Drop legacy-of-mm-gpiochip.h header

Remove legacy-of-mm-gpiochip.h header file, replace of_* functions
and structs with appropriate alternatives.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20241031101836.2434308-1-andriy.shevchenko@linux.intel.com


Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>