arm64: dts: imx8mp-debix-model-a: Remove USB hub reset-gpios

The SAI2_TXC pin is left unconnected per the imx8mp-debix-model-a
schematics:

https://debix.io/Uploads/Temp/file/20230331/DEBIX%20Model%20A%20Schematics.pdf

Also, the RTS5411E USB hub chip does not have a reset pin.

Remove this pin description to properly describe the hardware.

This also fixes the following schema warning:

hub@1: 'reset-gpios' does not match any of the regexes: 'pinctrl-[0-9]+'
from schema $id: http://devicetree.org/schemas/usb/realtek,rts5411.yaml#

Fixes: 0253e1cb ("arm64: dts: imx8mp-debix: add USB host support")
Signed-off-by: Fabio Estevam <festevam@denx.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8mp-debix-model-a.dts

@@ -284,7 +284,6 @@ &usb_dwc3_1 {
 	usb_hub_2_x: hub@1 {
 		compatible = "usbbda,5411";
 		reg = <1>;
-		reset-gpios = <&gpio4 25 GPIO_ACTIVE_LOW>;
 		vdd-supply = <&reg_usb_hub>;
 		peer-hub = <&usb_hub_3_x>;
 	};
@@ -293,7 +292,6 @@ usb_hub_2_x: hub@1 {
 	usb_hub_3_x: hub@2 {
 		compatible = "usbbda,411";
 		reg = <2>;
-		reset-gpios = <&gpio4 25 GPIO_ACTIVE_LOW>;
 		vdd-supply = <&reg_usb_hub>;
 		peer-hub = <&usb_hub_2_x>;
 	};
@@ -443,7 +441,6 @@ MX8MP_IOMUXC_UART4_TXD__UART4_DCE_TX				0x49
 	pinctrl_usb1: usb1grp {
 		fsl,pins = <
 			MX8MP_IOMUXC_GPIO1_IO14__USB2_OTG_PWR				0x10
-			MX8MP_IOMUXC_SAI2_TXC__GPIO4_IO25				0x19
 		>;
 	};