ARM: dts: iwg20d-q7-common: Fix touch controller probe failure

As per the iWave RZ/G1M schematic, the signal LVDS_PPEN controls the
supply voltage for the touch panel, LVDS receiver and RGB LCD panel. Add
a regulator for these device nodes and remove the powerdown-gpios
property from the lvds-receiver node as it results in a touch controller
driver probe failure.

Fixes: 6f89dd9e ("ARM: dts: iwg20d-q7-common: Add LCD support")
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://lore.kernel.org/r/20200924080535.3641-1-biju.das.jz@bp.renesas.comSigned-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

arch/arm/boot/dts/iwg20d-q7-common.dtsi

@@ -57,7 +57,7 @@ lcd_backlight: backlight {
 
 	lvds-receiver {
 		compatible = "ti,ds90cf384a", "lvds-decoder";
-		powerdown-gpios = <&gpio7 25 GPIO_ACTIVE_LOW>;
+		power-supply = <&vcc_3v3_tft1>;
 
 		ports {
 			#address-cells = <1>;
@@ -81,6 +81,7 @@ lvds_receiver_out: endpoint {
 	panel {
 		compatible = "edt,etm0700g0dh6";
 		backlight = <&lcd_backlight>;
+		power-supply = <&vcc_3v3_tft1>;
 
 		port {
 			panel_in: endpoint {
@@ -113,6 +114,17 @@ sndcodec: simple-audio-card,codec {
 		};
 	};
 
+	vcc_3v3_tft1: regulator-panel {
+		compatible = "regulator-fixed";
+
+		regulator-name = "vcc-3v3-tft1";
+		regulator-min-microvolt = <3300000>;
+		regulator-max-microvolt = <3300000>;
+		enable-active-high;
+		startup-delay-us = <500>;
+		gpio = <&gpio7 25 GPIO_ACTIVE_HIGH>;
+	};
+
 	vcc_sdhi1: regulator-vcc-sdhi1 {
 		compatible = "regulator-fixed";
 
@@ -207,6 +219,7 @@ touch: touchpanel@38 {
 		reg = <0x38>;
 		interrupt-parent = <&gpio2>;
 		interrupts = <12 IRQ_TYPE_EDGE_FALLING>;
+		vcc-supply = <&vcc_3v3_tft1>;
 	};
 };