common: dfu: saperate the dfu common functionality

The cmd_dfu functionality is been used by both SPL and
u-boot, saperating the core dfu functionality moving
it to common/dfu.c.

Signed-off-by: Ravi Babu <ravibabu@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/common/Makefile b/common/Makefile
index 6b4456e..ecc23e6 100644
--- a/common/Makefile
+++ b/common/Makefile
@@ -89,6 +89,7 @@
 endif # !CONFIG_SPL_BUILD
 
 ifdef CONFIG_SPL_BUILD
+obj-$(CONFIG_SPL_DFU_SUPPORT) += dfu.o
 obj-$(CONFIG_SPL_DFU_SUPPORT) += cli_hush.o
 obj-$(CONFIG_SPL_HASH_SUPPORT) += hash.o
 obj-$(CONFIG_ENV_IS_IN_FLASH) += env_flash.o
@@ -172,6 +173,7 @@
 
 obj-y += cli.o
 obj-$(CONFIG_CMDLINE) += cli_readline.o
+obj-$(CONFIG_CMD_DFU) += dfu.o
 obj-y += command.o
 obj-y += s_record.o
 obj-y += xyzModem.o