disabled by passing i8042.noacpi as a boot parameter.

Original code by Bjorn Helgaas <bjorn.helgaas@hp.com>, reworked by
Dmitry Torokhov <dtor@mail.ru>, FixedIO support from Hans-Frieder Vogt
<hfvogt@gmx.net>
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Vojtech Pavlik <vojtech@suse.cz>