arm64: dts: s32g2: Disable support for SD/eMMC UHS mode

Disable SD/eMMC UHS modes for NXP boards which do not set VCCQ voltage
supply to 1.8V by default, such as S32G274A-EVB and S32G274A-RDB2.

Signed-off-by: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
Reviewed-by: Matthias Brugger <mbrugger@suse.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

Author: Ciprian Marian Costea

arch/arm64/boot/dts/freescale/s32g274a-evb.dts

@@ -39,5 +39,6 @@
 	pinctrl-1 = <&pinctrl_usdhc0_100mhz>;
 	pinctrl-2 = <&pinctrl_usdhc0_200mhz>;
 	disable-wp;
+	no-1-8-v;
 	status = "okay";
 };

arch/arm64/boot/dts/freescale/s32g274a-rdb2.dts

@@ -45,5 +45,14 @@
 	pinctrl-1 = <&pinctrl_usdhc0_100mhz>;
 	pinctrl-2 = <&pinctrl_usdhc0_200mhz>;
 	disable-wp;
+	/* Remove no-1-8-v to enable higher speed modes for SD card.
+	 * However, this is not enough to enable HS400 or HS200 modes for eMMC.
+	 * In this case, the position of the resistor R797 must be changed
+	 * from A to B before removing the property.
+	 * If the property is removed without changing the resistor position,
+	 * HS*00 may be enabled, but the interface might be unstable because of
+	 * the wrong VCCQ voltage applied to the eMMC.
+	 */
+	no-1-8-v;
 	status = "okay";
 };