Bluetooth: btnxpuart: Fix sparse warnings

This fixes the following sparse warnings:

   drivers/bluetooth/btnxpuart.c:681:23: sparse: sparse:
   restricted __le16 degrades to integer
   drivers/bluetooth/btnxpuart.c:690:82: sparse:
   sparse: incorrect type in argument 2 (different base types)
   @@     expected unsigned short [usertype] req_len
   @@     got restricted __le16 [usertype] len @@
   drivers/bluetooth/btnxpuart.c:690:82: sparse:
   expected unsigned short [usertype] req_len
   drivers/bluetooth/btnxpuart.c:690:82: sparse:
   got restricted __le16 [usertype] len
   drivers/bluetooth/btnxpuart.c:694:84: sparse:
   sparse: incorrect type in argument 2 (different base types)
   @@     expected unsigned short [usertype] req_len
   @@     got restricted __le16 [usertype] len @@
   drivers/bluetooth/btnxpuart.c:694:84: sparse:
   expected unsigned short [usertype] req_len
   drivers/bluetooth/btnxpuart.c:694:84: sparse:
   got restricted __le16 [usertype] len
   drivers/bluetooth/btnxpuart.c:708:23: sparse:
   sparse: incorrect type in assignment (different base types)
   @@     expected unsigned int [usertype] requested_len
   @@     got restricted __le16 [usertype] len @@
   drivers/bluetooth/btnxpuart.c:708:23: sparse:
   expected unsigned int [usertype] requested_len
   drivers/bluetooth/btnxpuart.c:708:23: sparse:
   got restricted __le16 [usertype] len
   drivers/bluetooth/btnxpuart.c:787:78: sparse:
   sparse: incorrect type in argument 2 (different base types)
   @@     expected unsigned short [usertype] chipid
   @@     got restricted __le16 [usertype] chip_id @@
   drivers/bluetooth/btnxpuart.c:787:78: sparse:
   expected unsigned short [usertype] chipid
   drivers/bluetooth/btnxpuart.c:787:78: sparse:
   got restricted __le16 [usertype] chip_id
   drivers/bluetooth/btnxpuart.c:810:74: sparse:
   sparse: incorrect type in argument 2 (different base types)
   @@     expected unsigned short [usertype] req_len
   @@     got restricted __le16 [usertype] len @@
   drivers/bluetooth/btnxpuart.c:810:74: sparse:
   expected unsigned short [usertype] req_len
   drivers/bluetooth/btnxpuart.c:810:74: sparse:
   got restricted __le16 [usertype] len
   drivers/bluetooth/btnxpuart.c:815:76: sparse:
   sparse: incorrect type in argument 2 (different base types)
   @@     expected unsigned short [usertype] req_len
   @@     got restricted __le16 [usertype] len @@
   drivers/bluetooth/btnxpuart.c:815:76: sparse:
   expected unsigned short [usertype] req_len
   drivers/bluetooth/btnxpuart.c:815:76: sparse:
   got restricted __le16 [usertype] len
   drivers/bluetooth/btnxpuart.c:834:16: sparse:
   sparse: restricted __le32 degrades to integer
   drivers/bluetooth/btnxpuart.c:843:55: sparse:
   sparse: restricted __le32 degrades to integer
   drivers/bluetooth/btnxpuart.c:844:36: sparse:
   sparse: incorrect type in argument 3 (different base types)
   @@     expected unsigned long [usertype]
   @@     got restricted __le16 [usertype] len @@
   drivers/bluetooth/btnxpuart.c:844:36: sparse:
   expected unsigned long [usertype]
   drivers/bluetooth/btnxpuart.c:844:36: sparse:
   got restricted __le16 [usertype] len

Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/oe-kbuild-all/202304160736.Tsa0zTBU-lkp@intel.com/
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>