Input: i8042 - add TUXEDO BU1406 (N24_25BU) to the nomux list

TUXEDO BU1406 does not implement active multiplexing mode properly,
and takes around 550 ms in i8042_set_mux_mode(). Given that the
device does not have external AUX port, there is no downside in
disabling the MUX mode.

Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Suggested-by: Vojtech Pavlik <vojtech@suse.cz>
Reviewed-by: Marcos Paulo de Souza <marcos.souza.org@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>