arm: mvebu: clearfog: add MMC to SPL DT

This allows SPL to load the main U-Boot image from MMC once DM_MMC is
enabled.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Reviewed-by: Stefan Roese <sr@denx.de>
Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/arch/arm/dts/armada-388-clearfog-u-boot.dtsi b/arch/arm/dts/armada-388-clearfog-u-boot.dtsi
index f31691e..a12694e 100644
--- a/arch/arm/dts/armada-388-clearfog-u-boot.dtsi
+++ b/arch/arm/dts/armada-388-clearfog-u-boot.dtsi
@@ -7,3 +7,7 @@
 		u-boot,dm-spl;
 	};
 };
+
+&sdhci {
+	u-boot,dm-spl;
+};