dfu: Increase DFU buffer size from 4MiB to 8MiB

Increase size of DMA buffer from 4MiB to 8MiB. This is necessary due to
uImage size increase.

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>

include/dfu.h

@@ -59,7 +59,7 @@ static inline unsigned int get_mmc_blk_size(int dev)
 
 #define DFU_NAME_SIZE 32
 #define DFU_CMD_BUF_SIZE 128
-#define DFU_DATA_BUF_SIZE (1024*1024*4) /* 4 MiB */
+#define DFU_DATA_BUF_SIZE (1024*1024*8) /* 8 MiB */
 
 struct dfu_entity {
 	char			name[DFU_NAME_SIZE];