mtd: denali: make init function static

It's only used in this file.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

drivers/mtd/nand/denali.c

@@ -1394,7 +1394,7 @@ static struct nand_bbt_descr bbt_mirror_descr = {
 };
 
 /* initialize driver data structures */
-void denali_drv_init(struct denali_nand_info *denali)
+static void denali_drv_init(struct denali_nand_info *denali)
 {
 	denali->idx = 0;