net: de4x5: constify eisa_device_id

eisa_device_id are not supposed to change at runtime. All functions
working with eisa_device_id provided by <linux/eisa.h> work with
const eisa_device_id. So mark the non-const structs as const.
Signed-off-by: NArvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/dec/tulip/de4x5.c

@@ -2094,7 +2094,7 @@ static int de4x5_eisa_remove(struct device *device)
 	return 0;
 }
 
-static struct eisa_device_id de4x5_eisa_ids[] = {
+static const struct eisa_device_id de4x5_eisa_ids[] = {
         { "DEC4250", 0 },	/* 0 is the board name index... */
         { "" }
 };