am335x: sl50: Add Device Tree Support and DM_MMC driver

This adds device tree and the DM_MMC driver for the SL50 board.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
diff --git a/configs/am335x_sl50_defconfig b/configs/am335x_sl50_defconfig
index 822f73d..8c62247 100644
--- a/configs/am335x_sl50_defconfig
+++ b/configs/am335x_sl50_defconfig
@@ -40,6 +40,9 @@
 CONFIG_ENV_IS_IN_MMC=y
 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG=y
 CONFIG_BOOTCOUNT_LIMIT=y
+CONFIG_DEFAULT_DEVICE_TREE="am335x-sl50"
+CONFIG_OF_CONTROL=y
+CONFIG_DM_MMC=y
 CONFIG_MMC_OMAP_HS=y
 CONFIG_MII=y
 CONFIG_DRIVER_TI_CPSW=y