dfu: MMC specific routines for DFU operation

Support for MMC storage devices to work with DFU framework.

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Marek Vasut <marex@denx.de>
diff --git a/drivers/dfu/Makefile b/drivers/dfu/Makefile
index 7736485..7b717bc 100644
--- a/drivers/dfu/Makefile
+++ b/drivers/dfu/Makefile
@@ -26,6 +26,7 @@
 LIB	= $(obj)libdfu.o
 
 COBJS-$(CONFIG_DFU_FUNCTION) += dfu.o
+COBJS-$(CONFIG_DFU_MMC) += dfu_mmc.o
 
 SRCS    := $(COBJS-y:.o=.c)
 OBJS	:= $(addprefix $(obj),$(COBJS-y))