[MTD] Fix a bad dependency in the Blackfin code

Fix a bad dependency in the Blackfin code on a RomFS config symbol that doesn't
exist upstream.

Signed-off-by: Bernd Schmidt <bernd.schmidt@analog.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Bernd Schmidt <bernd.schmidt@analog.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

arch/blackfin/kernel/process.c

@@ -337,7 +337,7 @@ int _access_ok(unsigned long addr, unsigned long size)
 	if (addr >= memory_mtd_end && (addr + size) <= physical_mem_end)
 		return 1;
 
-#ifdef CONFIG_ROMFS_MTD_FS
+#ifdef CONFIG_ROMFS_ON_MTD
 	/* For XIP, allow user space to use pointers within the ROMFS.  */
 	if (addr >= memory_mtd_start && (addr + size) <= memory_mtd_end)
 		return 1;