Blackfin arch: ISP1761 doesn't work for USB flash disk

ZONE_DMA is required for some drivers subsystem, such as USB/SCSI.
Signed-off-by: NAubrey Li <aubrey.li@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

arch/blackfin/Kconfig

@@ -25,6 +25,10 @@ config BLACKFIN
 	bool
 	default y
 
+config ZONE_DMA
+	bool
+	default y
+
 config BFIN
 	bool
 	default y

arch/blackfin/mm/init.c

@@ -116,7 +116,8 @@ void paging_init(void)
 	{
 		unsigned long zones_size[MAX_NR_ZONES] = { 0, };
 
-		zones_size[ZONE_NORMAL] = (end_mem - PAGE_OFFSET) >> PAGE_SHIFT;
+		zones_size[ZONE_DMA] = (end_mem - PAGE_OFFSET) >> PAGE_SHIFT;
+		zones_size[ZONE_NORMAL] = 0;
 #ifdef CONFIG_HIGHMEM
 		zones_size[ZONE_HIGHMEM] = 0;
 #endif