ARM: davinci: da850evm: Support DM_MMC

With the updated driver available to support DM_MMC, this patch
enables DM_MMC for da850evm.

Signed-off-by: Adam Ford <aford173@gmail.com>
diff --git a/configs/da850evm_defconfig b/configs/da850evm_defconfig
index e81efe8..c30f396 100644
--- a/configs/da850evm_defconfig
+++ b/configs/da850evm_defconfig
@@ -43,6 +43,7 @@
 CONFIG_DA8XX_GPIO=y
 CONFIG_DM_I2C=y
 CONFIG_SYS_I2C_DAVINCI=y
+CONFIG_DM_MMC=y
 CONFIG_MTD_DEVICE=y
 CONFIG_MTD_PARTITIONS=y
 CONFIG_DM_SPI_FLASH=y