scsi: aha1542: constify pnp_device_id

pnp_device_id are not supposed to change at runtime. All functions
working with pnp_device_id provided by <linux/pnp.h> work with const
pnp_device_id. So mark the non-const structs as const.
Signed-off-by: NArvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/aha1542.c

@@ -986,7 +986,7 @@ static struct isa_driver aha1542_isa_driver = {
 static int isa_registered;
 
 #ifdef CONFIG_PNP
-static struct pnp_device_id aha1542_pnp_ids[] = {
+static const struct pnp_device_id aha1542_pnp_ids[] = {
 	{ .id = "ADP1542" },
 	{ .id = "" }
 };