FROMLIST: arm64: dts: qcom: monaco-evk: enable UART6 for robot board

The monaco-evk mezzanine connector supports a robot expansion board that
requires UART6, which is currently disabled. This prevents the expansion
board from exchanging data and control commands.

Enable UART6 and assign the serial2 alias to provide stable device
enumeration for the expansion board.

Link: https://lore.kernel.org/all/20260327083101.1343613-3-canfeng.zhuang@oss.qualcomm.com/
Signed-off-by: Canfeng Zhuang <canfeng.zhuang@oss.qualcomm.com>

Author: Canfeng Zhuang

arch/arm64/boot/dts/qcom/monaco-evk.dts

@@ -22,6 +22,7 @@
 		i2c1 = &i2c1;
 		serial0 = &uart7;
 		serial1 = &uart2;
+		serial2 = &uart6;
 	};
 
 	chosen {
@@ -937,6 +938,10 @@
 	};
 };
 
+&uart6 {
+	status = "okay";
+};
+
 &uart7 {
 	status = "okay";
 };