Bluetooth: btnxpuart: Fix compiler warnings

This fixes the follwing compiler warning reported by kernel test robot:

  drivers/bluetooth/btnxpuart.c:1332:34: warning: unused variable
  'nxpuart_of_match_table' [-Wunused-const-variable]

Signed-off-by: Neeraj Sanjay Kale <neeraj.sanjaykale@nxp.com>
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/oe-kbuild-all/202305161345.eClvTYQ9-lkp@intel.com/


Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>