iwlwifi: mvm: BT Coex - fix shared antenna check with new API

iwlwifi: mvm: BT Coex - fix shared antenna check with new API

The commit below fixed this for the old firmware API only.
Since the new firmware API hasn't been released yet, this
doesn't fix anything on currently existing firmwares.
This completes:

commit afcee962b09842d0f4191beb4a2d08251b4c7705
Author: Eyal Shapira <eyal@wizery.com>
Date:   Mon Feb 9 15:18:17 2015 +0200

    iwlwifi: mvm: fix BT coex shared antenna activity check

type=bugfix
bug=not-tracked
fixes=unknown

Reviewed-by: Eyal Shapira <eyal@wizery.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>