mei: enable async event notifications only from hbm version 2.0

Only FW version 2.0 and newer support the async event
notification. For backward compatibility block the feature
if the FW version is older then 2.0

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>