arm64: dts: ti: k3-j721s2: Convert usb_serdes_mux node into reg-mux

This removes a dependency on the parent node being a syscon node.
Convert from mmio-mux to reg-mux adjusting node name and properties
as needed.
Signed-off-by: Andrew Davis <afd@ti.com>
Link: https://lore.kernel.org/r/20240124184722.150615-7-afd@ti.comSigned-off-by: Vignesh Raghavendra <vigneshr@ti.com>

arch/arm64/boot/dts/ti/k3-j721s2-main.dtsi

@@ -45,7 +45,7 @@ scm_conf: syscon@104000 {
 		ranges = <0x00 0x00 0x00104000 0x18000>;
 
 		usb_serdes_mux: mux-controller@0 {
-			compatible = "mmio-mux";
+			compatible = "reg-mux";
 			reg = <0x0 0x4>;
 			#mux-control-cells = <1>;
 			mux-reg-masks = <0x0 0x8000000>; /* USB0 to SERDES0 lane 1/3 mux */