mtd: mark const init data with __initconst instead of __initdata

As long as there is no other non-const variable marked __initdata in the
same compilation unit it doesn't hurt. If there were one however
compilation would fail with

	error: $variablename causes a section type conflict

because a section containing const variables is marked read only and so
cannot contain non-const variables.
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

drivers/mtd/maps/wr_sbc82xx_flash.c

@@ -59,7 +59,7 @@ static struct mtd_partition bigflash_parts[] = {
 	}
 };
 
-static const char *part_probes[] __initdata = {"cmdlinepart", "RedBoot", NULL};
+static const char *part_probes[] __initconst = {"cmdlinepart", "RedBoot", NULL};
 
 #define init_sbc82xx_one_flash(map, br, or)			\
 do {								\