arm64: dts: rockchip: Add rtc0 alias for NanoPi R5S + R5C

The RTC_HCTOSYS_DEVICE module defaults to rtc0 and should (highly)
preferable be assigned to a battery backed RTC module as it is used to
(re)initialize the system clock.

The R5S and R5C have a connector for a RTC battery which is used by
HYM8563 RTC. Both devices also have another RTC from the rk809 PMIC.
To make sure the HYM8563 is always assigned rtc0, add an alias for it.

Signed-off-by: Diederik de Haas <didi.debian@cknow.org>
Link: https://lore.kernel.org/r/20250713161723.270963-1-didi.debian@cknow.org
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

Author: diederikdehaas

arch/arm64/boot/dts/rockchip/rk3568-nanopi-r5s.dtsi

@@ -18,6 +18,7 @@
 	aliases {
 		mmc0 = &sdmmc0;
 		mmc1 = &sdhci;
+		rtc0 = &hym8563;
 	};
 
 	chosen: chosen {