i40e: use i40e_stop_rings_no_wait to implement PORT_SUSPENDED state

This state bit was added as a way for DCB to avoid having to wait for
the queues to disable when handling LLDP events. The logic for this was
burried deep within stop Tx and stop Rx queue code. First, let's rename
it so that it does not appear to only affect Tx when infact it modifies
both Tx and Rx flow. Second we can move it up into the i40e_stop_rings()
function, and we can simply re-use the i40e_stop_rings_no_wait() so that
we don't have to bury the implementation as deep into the call stack.

An alternative might be to remove the state bit and instead attempt to
shut down everything directly in DCP flow. This, however, is not ideal
because it creates yet another separate shutdown routine that we'd have
to maintain. In the current implementation any changes will be made to
both flows.

Change-ID: I68e1ccb901af320862bca395e9c9746f08e8b17c
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>