arm: dts: k3-j721e-mcu-wakeup: Add HyperBus Controller node

Add DT node for HyperBus Memory Controller and hbmc-mux in the
FSS. hbmc-am654 driver uses syscon_get_regmap() call which fails
with current compatible setting.

Signed-off-by: Vaishnav Achath <vaishnav.a@ti.com>
diff --git a/arch/arm/dts/k3-j721e-mcu-wakeup.dtsi b/arch/arm/dts/k3-j721e-mcu-wakeup.dtsi
index d2dceda..22166c7 100644
--- a/arch/arm/dts/k3-j721e-mcu-wakeup.dtsi
+++ b/arch/arm/dts/k3-j721e-mcu-wakeup.dtsi
@@ -170,12 +170,30 @@
 	};
 
 	fss: fss@47000000 {
-		compatible = "simple-bus";
+		compatible = "syscon", "simple-mfd";
 		reg = <0x0 0x47000000 0x0 0x100>;
 		#address-cells = <2>;
 		#size-cells = <2>;
 		ranges;
 
+		hbmc_mux: hbmc-mux {
+			compatible = "mmio-mux";
+			#mux-control-cells = <1>;
+			mux-reg-masks = <0x4 0x2>; /* HBMC select */
+		};
+
+		hbmc: hyperbus@47034000 {
+			compatible = "ti,j721e-hbmc", "ti,am654-hbmc";
+			reg = <0x0 0x47034000 0x0 0x100>,
+				<0x5 0x00000000 0x1 0x0000000>;
+			power-domains = <&k3_pds 102 TI_SCI_PD_EXCLUSIVE>;
+			#address-cells = <2>;
+			#size-cells = <1>;
+			mux-controls = <&hbmc_mux 0>;
+			assigned-clocks = <&k3_clks 102 0>;
+			assigned-clock-rates = <250000000>;
+		};
+
 		ospi0: spi@47040000 {
 			compatible = "ti,am654-ospi", "cdns,qspi-nor";
 			reg = <0x0 0x47040000 0x0 0x100>,