arm64: dts: ti: k3-am654-base-board: Add VTT GPIO regulator for DDR

Hold the DDR vtt regulator active for functionality.
Signed-off-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Kamlesh Gurudasani <kamlesh@ti.com>
Link: https://lore.kernel.org/r/20230419225913.663448-4-nm@ti.comSigned-off-by: Vignesh Raghavendra <vigneshr@ti.com>

arch/arm64/boot/dts/ti/k3-am654-base-board.dts

@@ -116,6 +116,20 @@ vdd_mmc1_sd: regulator-2 {
 		vin-supply = <&vcc3v3_io>;
 		gpio = <&pca9554 4 GPIO_ACTIVE_HIGH>;
 	};
+
+	vtt_supply: regulator-3 {
+		compatible = "regulator-fixed";
+		regulator-name = "vtt";
+		pinctrl-names = "default";
+		pinctrl-0 = <&ddr_vtt_pins_default>;
+		regulator-min-microvolt = <3300000>;
+		regulator-max-microvolt = <3300000>;
+		enable-active-high;
+		regulator-always-on;
+		regulator-boot-on;
+		vin-supply = <&vcc3v3_io>;
+		gpio = <&wkup_gpio0 28 GPIO_ACTIVE_HIGH>;
+	};
 };
 
 &wkup_pmx0 {
@@ -128,6 +142,12 @@ AM65X_WKUP_IOPAD(0x00cc, PIN_OUTPUT, 1)	/* (AC1) WKUP_GPIO0_7.WKUP_UART0_RTSn */
 		>;
 	};
 
+	ddr_vtt_pins_default: ddr-vtt-pins-default {
+		pinctrl-single,pins = <
+			AM65X_WKUP_IOPAD(0x0040, PIN_OUTPUT_PULLUP, 7)	/* WKUP_GPIO0_28 */
+		>;
+	};
+
 	wkup_i2c0_pins_default: wkup-i2c0-pins-default {
 		pinctrl-single,pins = <
 			AM65X_WKUP_IOPAD(0x00e0, PIN_INPUT, 0) /* (AC7) WKUP_I2C0_SCL */