mtd: maps: add const qualifiers

Be a bit stricter and add few more 'const' qualifiers.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/mtd/maps/pxa2xx-flash.c b/drivers/mtd/maps/pxa2xx-flash.c
index 43e3dbb..acb1dbc 100644
--- a/drivers/mtd/maps/pxa2xx-flash.c
+++ b/drivers/mtd/maps/pxa2xx-flash.c
@@ -45,9 +45,7 @@
 	struct map_info		map;
 };
 
-
-static const char *probes[] = { "RedBoot", "cmdlinepart", NULL };
-
+static const char * const probes[] = { "RedBoot", "cmdlinepart", NULL };
 
 static int pxa2xx_flash_probe(struct platform_device *pdev)
 {