[PATCH v2] dfu: Add proper dependency for CONFIG_DFU_MMC

[Ashok Reddy Soma]

When CONFIG_CMD_MMC and CONFIG_MMC are disabled, still some compilation
errors are seen as below due to unresolved symbols.

drivers/dfu/dfu_mmc.o: in function `mmc_block_op':
drivers/dfu/dfu_mmc.c:32: undefined reference to `find_mmc_device'
drivers/dfu/dfu_mmc.c:54: undefined reference to `mmc_get_blk_desc'
drivers/dfu/dfu_mmc.c:67: undefined reference to `mmc_get_blk_desc'
drivers/dfu/dfu_mmc.c:70: undefined reference to `mmc_get_blk_desc'
drivers/dfu/dfu_mmc.o: in function `dfu_fill_entity_mmc':
drivers/dfu/dfu_mmc.c:369: undefined reference to `find_mmc_device'
drivers/dfu/dfu_mmc.c:376: undefined reference to `mmc_init'
drivers/dfu/dfu_mmc.c:403: undefined reference to `mmc_get_blk_desc'
gnu/aarch64/lin/aarch64-linux/bin/aarch64-linux-gnu-ld.bfd: line 4:
31661 Segmentation fault      (core dumped) $CC --sysroot=$LIBC
--no-warn-rwx-segment "$@"
Makefile:1760: recipe for target 'u-boot' failed
make: *** [u-boot] Error 139
make: *** Deleting file 'u-boot'

Add dependency of CONFIG_MMC for CONFIG_DFU_MMC config to fix the errors.

Signed-off-by: Ashok Reddy Soma <ashok.reddy.soma at amd.com>
---

Changes in v2:
 - Changed patch subject prefix to dfu from zynqmp: config

 drivers/dfu/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/dfu/Kconfig b/drivers/dfu/Kconfig
index 8d7f13dcb0..8e9e8eb4fe 100644
--- a/drivers/dfu/Kconfig
+++ b/drivers/dfu/Kconfig
@@ -35,6 +35,7 @@ config DFU_TIMEOUT
 
 config DFU_MMC
 	bool "MMC back end for DFU"
+	depends on MMC
 	help
 	  This option enables using DFU to read and write to MMC based storage.
 
-- 
2.17.1