This seems to work perfectly OK on my ICH7 test machine and also it
works on QEMU, so it is probably OK to restore this.
This will ensure we always get scan code set 1 input, because we enable
scan code set 2 and PS/2 translation on the first (keyboard) port.
The setting of scan code set sequence is removed, as it's buggy and
could lead the controller to fail immediately when doing self-test
afterwards. We will restore it when we understand how to do so safely.
Allow the user to determine a preferred detection path with a new kernel
command line argument. The defualt option is to check i8042 presence
with an ACPI check and if necessary - an "aggressive" test to determine
i8042 existence in the system.
Also, keep the i8042 controller pointer on the stack, so don't assign
m_i8042_controller member pointer if it does not exist.
