When KBC is in active multiplexing mode, disabling and re-enabling the
touchpad with the special key leaves the touchpad dead. Since the laptop
does not have any external PS/2 ports disabling MUX mode should be safe.
Reported-by: NEugeniy Meshcheryakov <eugen@debian.org>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>