ARM: DTS: stm32: add MMC nodes for stm32f746-disco and stm32f769-disco

Add DT nodes to enable ARM_PL180_MMCI IP support for STM32F746
and STM32F769 discovery boards

There is a hardware issue on these boards, it misses a pullup on the GPIO line
used as card detect to allow correct SD card detection.
As workaround, cd-gpios property is not present in DT.
So SD card is always considered present in the slot.

Signed-off-by: Christophe Priouzeau <christophe.priouzeau@st.com>
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/dts/stm32f769-disco.dts b/arch/arm/dts/stm32f769-disco.dts
index f34ffcc..59c9d31 100644
--- a/arch/arm/dts/stm32f769-disco.dts
+++ b/arch/arm/dts/stm32f769-disco.dts
@@ -60,6 +60,7 @@
 	aliases {
 		serial0 = &usart1;
 		spi0 = &qspi;
+		mmc0 = &sdio2;
 		/* Aliases for gpios so as to use sequence */
 		gpio0 = &gpioa;
 		gpio1 = &gpiob;
@@ -252,3 +253,14 @@
 			reg = <0>;
 	};
 };
+
+&sdio2 {
+	status = "okay";
+	cd-gpios = <&gpioi 15 0>;
+	cd-inverted;
+	pinctrl-names = "default", "opendrain";
+	pinctrl-0 = <&sdio_pins_b>;
+	pinctrl-1 = <&sdio_pins_od_b>;
+	bus-width = <4>;
+	max-frequency = <25000000>;
+};