ARM: dts: rockchip: Fix RTC description on rk3288-firefly-reload

Node names should be generic, so use 'rtc'.

Remove 'clock-frequency' as is not a valid property.

This fixes the following dt-schema warnings:

'hym8563@51' does not match '^rtc(@.*|-([0-9]|[1-9][0-9]+))?$'
Unevaluated properties are not allowed ('clock-frequency' was unexpected)

Signed-off-by: Fabio Estevam <festevam@gmail.com>
Link: https://patch.msgid.link/20260303193855.828892-2-festevam@gmail.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

Author: fabioestevam

arch/arm/boot/dts/rockchip/rk3288-firefly-reload.dts

@@ -197,11 +197,10 @@
 };
 
 &i2c0 {
-	hym8563: hym8563@51 {
+	hym8563: rtc@51 {
 		compatible = "haoyu,hym8563";
 		reg = <0x51>;
 		#clock-cells = <0>;
-		clock-frequency = <32768>;
 		clock-output-names = "xin32k";
 		interrupt-parent = <&gpio7>;
 		interrupts = <RK_PA4 IRQ_TYPE_EDGE_FALLING>;