acer_acpi - Port over upstream work on AMW0 V2 and EC
The upstream acer-wmi work handles AMW0 devices via the WMID interface,
and not the old AMW0 one. Switch over to this, since it means we don't
need to keep track of as many EC quirks as possible.
On older AMW0 laptops, all of them seen so far have been confirmed to use
the same EC registers, so we'll unconditionally enable the old Aspire 5020
quirks for all AMW0 V1 laptops.
Future work for AMW0 V2 and WMID will include using WMI to detect what
hardware is available (e.g. bluetooth, and possibly also 3G) and also
detecting the maximum brightness (reducing further the EC quirks we need
to store) (Autodetection is not practical on AMW0 V1, since this requires
poking at INT 15).