dt-bindings: gpio: nomadik: convert into yaml format

Create gpio/st,nomadik-gpio.yaml json-schema dt-bindings file as a
direct translation from gpio-nmk.txt. Remove the txt file.

Add clocks and gpio-ranges properties which were missing and are being
used in Nomadik devicetrees.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20240228-mbly-gpio-v2-1-3ba757474006@bootlin.com


[Dropped an unused label]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>