i40iw: Move cqp_cmd_head init to CQP initialization

Control QP (CQP) command backlog list is initialized at
device initialization time.  It is not reinitialized in
the reset flow.  Move the initialization to CQP creation
time so the list can be initialized correctly for reset as well.

Fixes: 86dbcd0f ("i40iw: add file to handle cqp calls")
Signed-off-by: Bob Sharp <Robert.O.Sharp@intel.com>
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>