With win8 capabiltiy, the machine will boot itself immediately after
shutdown command has executed.
Work around this issue by disabling win8 capcability. This workaround
also makes wireless hotkey work.
Signed-off-by: Edward Lin <yidi.lin@canonical.com> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>