mt76: make const array 'data' static, shrinks object size

Don't populate the const array 'data' on the stack but instead
make it static. Makes the object code smaller by 78 bytes:

Before:
   text    data     bss     dec     hex filename
   5438    1080       0    6518    1976 mediatek/mt76/mt76x2/usb_mcu.o

After:
   text    data     bss     dec     hex filename
   5296    1144       0    6440    1928 mediatek/mt76/mt76x2/usb_mcu.o

(gcc version 8.2.0 x86_64)
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mt76x2/usb_mcu.c

@@ -39,7 +39,7 @@ static void mt76x2u_mcu_load_ivb(struct mt76x02_dev *dev)
 static void mt76x2u_mcu_enable_patch(struct mt76x02_dev *dev)
 {
 	struct mt76_usb *usb = &dev->mt76.usb;
-	const u8 data[] = {
+	static const u8 data[] = {
 		0x6f, 0xfc, 0x08, 0x01,
 		0x20, 0x04, 0x00, 0x00,
 		0x00, 0x09, 0x00,