serial: liteuart: fix use-after-free and memleak on unbind

serial: liteuart: fix use-after-free and memleak on unbind

commit 05f929b395dec8957b636ff14e66b277ed022ed9 upstream.

Deregister the port when unbinding the driver to prevent it from being
used after releasing the driver data and leaking memory allocated by
serial core.

Fixes: 1da81e5562fa ("drivers/tty/serial: add LiteUART driver")
Cc: stable@vger.kernel.org      # 5.11
Cc: Filip Kokosinski <fkokosinski@antmicro.com>
Cc: Mateusz Holenko <mholenko@antmicro.com>
Reviewed-by: Stafford Horne <shorne@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20211117100512.5058-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>