mt76: Fix undefined behavior due to shift overflowing the constant

Fix:

  drivers/net/wireless/mediatek/mt76/mt76x2/pci.c: In function ‘mt76x2e_probe’:
  ././include/linux/compiler_types.h:352:38: error: call to ‘__compiletime_assert_946’ \
	declared with attribute error: FIELD_PREP: mask is not constant
    _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)

See https://lore.kernel.org/r/YkwQ6%2BtIH8GQpuct@zn.tnic for the gory
details as to why it triggers with older gccs only.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Felix Fietkau <nbd@nbd.name>
Cc: Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
Cc: Ryder Lee <ryder.lee@mediatek.com>
Cc: Shayne Chen <shayne.chen@mediatek.com>
Cc: Sean Wang <sean.wang@mediatek.com>
Cc: Kalle Valo <kvalo@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220405151517.29753-9-bp@alien8.de

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

@@ -80,7 +80,7 @@ mt76x2e_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	mt76_rmw_field(dev, 0x15a10, 0x1f << 16, 0x9);
 
 	/* RG_SSUSB_G1_CDR_BIC_LTR = 0xf */
-	mt76_rmw_field(dev, 0x15a0c, 0xf << 28, 0xf);
+	mt76_rmw_field(dev, 0x15a0c, 0xfU << 28, 0xf);
 
 	/* RG_SSUSB_CDR_BR_PE1D = 0x3 */
 	mt76_rmw_field(dev, 0x15c58, 0x3 << 6, 0x3);