ata: pata_octeon_cf: make of_device_ids const.

of_device_ids are not supposed to change at runtime. All functions
working with of_device_ids provided by <linux/of.h> work with const
of_device_ids. So mark the non-const structs as const.

File size before:
   text	   data	    bss	    dec	    hex	filename
    465	    696	      4	   1165	    48d	drivers/ata/pata_octeon_cf.o

File size after constify octeon_cf_match.
   text	   data	    bss	    dec	    hex	filename
    865	    280	      4	   1149	    47d	drivers/ata/pata_octeon_cf.o

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

drivers/ata/pata_octeon_cf.c

@@ -1038,7 +1038,7 @@ static void octeon_cf_shutdown(struct device *dev)
 	}
 }
 
-static struct of_device_id octeon_cf_match[] = {
+static const struct of_device_id octeon_cf_match[] = {
 	{
 		.compatible = "cavium,ebt3000-compact-flash",
 	},