dt-bindings: rtc: moxart: use proper names for gpio properties

MOXA ART RTC driver has been switched to gpiod API and is now using
properly named properties for its gpios (with gpiolib implementing a
quirk to recognize legacy names). Change binding document to use
proper names as well.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Link: https://lore.kernel.org/r/20230201054815.4112632-2-dmitry.torokhov@gmail.com


Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>