ARM: imx6: DHCOM i.MX6 PDK: defconfig: Enable MMC support of SPL

Signed-off-by: Claudius Heine <ch@denx.de>
diff --git a/configs/dh_imx6_defconfig b/configs/dh_imx6_defconfig
index db4753c..072dcb2 100644
--- a/configs/dh_imx6_defconfig
+++ b/configs/dh_imx6_defconfig
@@ -6,6 +6,7 @@
 CONFIG_SPL_LIBGENERIC_SUPPORT=y
 CONFIG_MX6_DDRCAL=y
 CONFIG_TARGET_DHCOMIMX6=y
+CONFIG_SPL_MMC_SUPPORT=y
 CONFIG_SPL_SERIAL_SUPPORT=y
 CONFIG_NR_DRAM_BANKS=1
 CONFIG_SPL=y