arm64: dts: imx8mq-librem5-devkit: Drop power-supply

It's not a valid binding. Instead move the sdio_rst line to the power
sequence and use w_disable1 as the vmmc-supply bringing it more in line
with other SDIO M2 cards.

Resolves following warning:

arch/arm64/boot/dts/freescale/imx8mq-librem5-devkit.dtb: mmc@30b50000: Unevaluated properties are not allowed ('power-supply' was unexpected)
        from schema $id: http://devicetree.org/schemas/mmc/fsl-imx-esdhc.yaml#

Reported-by: David Heidelberg <david@ixit.cz>
Signed-off-by: Guido Günther <agx@sigxcpu.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

Author: agx

arch/arm64/boot/dts/freescale/imx8mq-librem5-devkit.dts

@@ -139,18 +139,6 @@
 		regulator-always-on;
 	};
 
-	reg_usdhc2_vmmc: regulator-usdhc2-vmmc {
-		compatible = "regulator-fixed";
-		pinctrl-names = "default";
-		pinctrl-0 = <&pinctrl_usdhc2_pwr>;
-		regulator-name = "VSD_3V3";
-		regulator-min-microvolt = <3300000>;
-		regulator-max-microvolt = <3300000>;
-		gpio = <&gpio2 19 GPIO_ACTIVE_HIGH>;
-		enable-active-high;
-		regulator-always-on;
-	};
-
 	wwan_codec: sound-wwan-codec {
 		compatible = "option,gtm601";
 		#sound-dai-cells = <0>;
@@ -242,6 +230,13 @@
 		enable-active-high;
 		regulator-always-on;
 	};
+
+	wifi_pwr_seq: pwrseq {
+		pinctrl-names = "default";
+		pinctrl-0 = <&pinctrl_usdhc2_rst>;
+		compatible = "mmc-pwrseq-simple";
+		reset-gpios = <&gpio2 19 GPIO_ACTIVE_LOW>;
+	};
 };
 
 &A53_0 {
@@ -808,7 +803,7 @@
 		>;
 	};
 
-	pinctrl_usdhc2_pwr: usdhc2pwrgrp {
+	pinctrl_usdhc2_rst: usdhc2rstgrp {
 		fsl,pins = <
 			MX8MQ_IOMUXC_SD2_RESET_B_GPIO2_IO19	0x41
 		>;
@@ -1031,8 +1026,8 @@
 	pinctrl-1 = <&pinctrl_usdhc2_100mhz>;
 	pinctrl-2 = <&pinctrl_usdhc2_200mhz>;
 	bus-width = <4>;
-	vmmc-supply = <&reg_usdhc2_vmmc>;
-	power-supply = <&wifi_pwr_en>;
+	vmmc-supply = <&wifi_pwr_en>;
+	mmc-pwrseq = <&wifi_pwr_seq>;
 	broken-cd;
 	disable-wp;
 	cap-sdio-irq;