Bluetooth: mediatek: Fixed incorrect type in assignment

Fixed warning: incorrect type in assignment reported by kbuild test robot.
The detailed warning is shown as below.

make ARCH=x86_64 allmodconfig
make C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__'

All warnings (new ones prefixed by >>):

btmtkuart.c:671:18: sparse:    warning: incorrect type in assignment
			       (different base types)
btmtkuart.c:671:18: sparse:    expected unsigned int [usertype] baudrate
btmtkuart.c:671:18: sparse:    got restricted __le32 [usertype]

sparse warnings: (new ones prefixed by >>)
btmtkuart.c:671:18: sparse: warning: incorrect type in assignment
			       (different base types)
btmtkuart.c:671:18: sparse:    expected unsigned int [usertype] baudrate
btmtkuart.c:671:18: sparse:    got restricted __le32 [usertype]

vim +671 drivers/bluetooth/btmtkuart.c

   659
   660	static int btmtkuart_change_baudrate(struct hci_dev *hdev)
   661	{
   662		struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
   663		struct btmtk_hci_wmt_params wmt_params;
   664		u32 baudrate;
   665		u8 param;
   666		int err;
   667
   668		/* Indicate the device to enter the probe state the host is
   669		 * ready to change a new baudrate.
   670		 */
 > 671		baudrate = cpu_to_le32(bdev->desired_speed);
   672		wmt_params.op = MTK_WMT_HIF;

Fixes: 22eaf6c9 ("Bluetooth: mediatek: add support for MediaTek MT7663U and MT7668U UART devices")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

drivers/bluetooth/btmtkuart.c

@@ -661,7 +661,7 @@ static int btmtkuart_change_baudrate(struct hci_dev *hdev)
 {
 	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
 	struct btmtk_hci_wmt_params wmt_params;
-	u32 baudrate;
+	__le32 baudrate;
 	u8 param;
 	int err;