ice: Add helper function for adding VLAN 0

There are multiple places where VLAN 0 is being added. Create a function
to be called in order to minimize changes as the implementation is expanded
to support double VLAN and avoid duplicated code.

Signed-off-by: Brett Creeley <brett.creeley@intel.com>
Tested-by: Gurucharan G <gurucharanx.g@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>