stm32mp1: add eMMC support for ED1

Add command GPT support
Add EMMC boot support
Add the 2 other SDMMC instances for ED1:
- SDMMC2 = mmc 1, eMMC on the ED1 board
- SDMMC3 = extension connector, deactivated by default

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
diff --git a/arch/arm/dts/stm32mp157c-ed1-u-boot.dtsi b/arch/arm/dts/stm32mp157c-ed1-u-boot.dtsi
index 94d27fb..5d43753 100644
--- a/arch/arm/dts/stm32mp157c-ed1-u-boot.dtsi
+++ b/arch/arm/dts/stm32mp157c-ed1-u-boot.dtsi
@@ -11,6 +11,7 @@
 / {
 	aliases {
 		mmc0 = &sdmmc1;
+		mmc1 = &sdmmc2;
 		i2c3 = &i2c4;
 	};
 };
@@ -77,6 +78,7 @@
 		CLK_SDMMC12_PLL3R
 		CLK_I2C46_PCLK5
 		CLK_I2C12_PCLK1
+		CLK_SDMMC3_PLL3R
 		CLK_I2C35_PCLK1
 		CLK_UART1_PCLK5
 		CLK_UART24_PCLK1
@@ -131,3 +133,22 @@
 &sdmmc1 {
 	u-boot,dm-spl;
 };
+
+/* MMC2 boot */
+&sdmmc2_b4_pins_a {
+	u-boot,dm-spl;
+	pins {
+		u-boot,dm-spl;
+	};
+};
+
+&sdmmc2_d47_pins_a {
+	u-boot,dm-spl;
+	pins {
+		u-boot,dm-spl;
+	};
+};
+
+&sdmmc2 {
+	u-boot,dm-spl;
+};