pinctrl: bcm2835: Switch to use ->add_pin_ranges()

pinctrl: bcm2835: Switch to use ->add_pin_ranges()

Yeah, while the ->add_pin_ranges() shouldn't be used by DT drivers,
this one requires it to support quite old firmware descriptions that
do not have gpio-ranges property.

The change allows to clean up GPIO library from OF specifics.
There is no functional change intended.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Link: https://lore.kernel.org/r/20230113215352.44272-4-andriy.shevchenko@linux.intel.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>