On some boxes that don't have PS/2 mice connected at startup BIOS
completely disables AUX port and attempts to access it result in
hosed keyboard. Historically we do not trust ACPI/PNP data on
i386 and try to poke AUX port even if we did not find an active
PNP node for it. However in cases when BIOS writers got KBD port
properly described we can assume that they did the right thing
for AUX port as well.
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>