arm64: dts: ti: k3-j721e: 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/20240124184722.150615-6-afd@ti.comSigned-off-by: Vignesh Raghavendra <vigneshr@ti.com>

arch/arm64/boot/dts/ti/k3-j721e-main.dtsi

@@ -70,10 +70,11 @@ cpsw0_phy_gmii_sel: phy@4044 {
 		};
 
 		usb_serdes_mux: mux-controller@4000 {
-			compatible = "mmio-mux";
+			compatible = "reg-mux";
+			reg = <0x4000 0x20>;
 			#mux-control-cells = <1>;
-			mux-reg-masks = <0x4000 0x8000000>, /* USB0 to SERDES0/3 mux */
-					<0x4010 0x8000000>; /* USB1 to SERDES1/2 mux */
+			mux-reg-masks = <0x0 0x8000000>, /* USB0 to SERDES0/3 mux */
+					<0x10 0x8000000>; /* USB1 to SERDES1/2 mux */
 		};
 
 		ehrpwm_tbclk: clock-controller@4140 {