riscv: dts: sophgo: sophgo-srd3-10: reserve uart0 device

As the uart0 is already occupied by the firmware, reserve it
to avoid this port is used by mistake.

Tested-by: Han Gao <rabenda.cn@gmail.com>
Reviewed-by: Chen Wang <wangchen20@iscas.ac.cn>
Link: https://lore.kernel.org/r/20250703004024.85221-1-inochiama@gmail.com
Signed-off-by: Inochi Amaoto <inochiama@gmail.com>
Signed-off-by: Chen Wang <unicorn_wang@outlook.com>
Signed-off-by: Chen Wang <wangchen20@iscas.ac.cn>

Author: inochisa

arch/riscv/boot/dts/sophgo/sg2044-sophgo-srd3-10.dts

@@ -109,6 +109,11 @@
 	status = "okay";
 };
 
+&uart0 {
+	/* for firmware */
+	status = "reserved";
+};
+
 &uart1 {
 	status = "okay";
 };