Input: i8042 - disable mux on Toshiba C850D

commit 8669cf6793bb38307a30fb6b9565ddc8840ebd3f upstream.

On Toshiba Satellite C850D, the touchpad and the keyboard might randomly
not work at boot. Preventing MUX mode activation solves this issue.

Signed-off-by: Anisse Astier <anisse@astier.eu>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>