config: rk3399: enable dwmmc controller

Enable the rockchip dwmmc driver for rk3399 and its evb.

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/evb-rk3399_defconfig b/configs/evb-rk3399_defconfig
index 3f9b47e..cd06cae 100644
--- a/configs/evb-rk3399_defconfig
+++ b/configs/evb-rk3399_defconfig
@@ -21,6 +21,7 @@
 CONFIG_FIT=y
 CONFIG_SYSRESET=y
 CONFIG_DM_MMC=y
+CONFIG_ROCKCHIP_DWMMC=y
 CONFIG_ROCKCHIP_SDHCI=y
 CONFIG_PINCTRL=y
 CONFIG_RAM=y