ARM: dts: rockchip: Fix RTC compatible on rk3288-phycore-rdk

According to st,m41t80.yaml, the correct compatible for the RV4162 RTC
is "microcrystal,rv4162".

Fix it accordingly.

This fixes the following dt-schema warning:

rtc@68: failed to match any schema with compatible: ['rv4162']

Signed-off-by: Fabio Estevam <festevam@gmail.com>
Link: https://patch.msgid.link/20260301124156.473862-1-festevam@gmail.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

Author: fabioestevam

arch/arm/boot/dts/rockchip/rk3288-phycore-rdk.dts

@@ -94,7 +94,7 @@
 	};
 
 	i2c_rtc: rtc@68 {
-		compatible = "rv4162";
+		compatible = "microcrystal,rv4162";
 		reg = <0x68>;
 		pinctrl-names = "default";
 		pinctrl-0 = <&i2c_rtc_int>;