nds32: mmc: Support ftsdc010 DM.

Add nds32_mmc to support ftsdc010 dm flow.

Signed-off-by: Rick Chen <rick@andestech.com>
diff --git a/drivers/mmc/Makefile b/drivers/mmc/Makefile
index d505f37..9af375b 100644
--- a/drivers/mmc/Makefile
+++ b/drivers/mmc/Makefile
@@ -44,6 +44,7 @@
 obj-$(CONFIG_SH_MMCIF) += sh_mmcif.o
 obj-$(CONFIG_SH_SDHI) += sh_sdhi.o
 obj-$(CONFIG_STM32_SDMMC2) += stm32_sdmmc2.o
+obj-$(CONFIG_MMC_NDS32) += nds32_mmc.o
 
 # SDHCI
 obj-$(CONFIG_MMC_SDHCI)			+= sdhci.o