The 900A provides hotplug notifications on a different ACPI object to
other models.
Reported-by: NTrevor <trevor.chart@gmail.com>
Signed-off-by: NAlan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: NCorentin Chary <corentincj@iksaif.net>
Signed-off-by: NLen Brown <len.brown@intel.com>