arm64: dts: imx8mq-librem5-devkit: Disable snvs_rtc

The board has it's own RTC chip which is backed by the (optional)
battery and hence preserves data/time on poweroff when that is inserted.
Signed-off-by: NGuido Günther <agx@sigxcpu.org>
Reviewed-by: NKrzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: NShawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8mq-librem5-devkit.dts

@@ -897,6 +897,10 @@
 	status = "okay";
 };
 
+&snvs_rtc {
+	status = "disabled";
+};
+
 &sai2 {
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_sai2>;