dt-bindings: rtc: renesas,rz-rtca3: Add RZ/V2H support

dt-bindings: rtc: renesas,rz-rtca3: Add RZ/V2H support

The Renesas RZ/V2H RTC IP is based on the same RTCA3 IP as RZ/G3S
(r9a08g045), with the following differences:
- It lacks the time capture functionality
- The maximum supported periodic interrupt frequency is 128Hz instead
  of 256Hz
- It requires two reset lines instead of one

Add new compatible string "renesas,r9a09g057-rtca3" for RZ/V2H and update
the binding accordingly:
- Allow "resets" to contain one or two entries depending on the SoC.
- Add "reset-names" property, but make it required only for RZ/V2H.

Signed-off-by: Ovidiu Panait <ovidiu.panait.rb@renesas.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://patch.msgid.link/20251107210706.45044-2-ovidiu.panait.rb@renesas.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>