dt-bindings: rtc: sun6i: Add Allwinner A523 support

The RTC in the Allwinner A523 SoC is compatible to the D1 and R329, so
just add its name and use the R329 as a fallback.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20241111013033.22793-11-andre.przywara@arm.com


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