ixgbe: DCB, do not call set_state() from IEEE mode

The DCB CEE command set_state() will complete successfully
but is misleading because it enables IEEE mode. After
this patch the command is failed.

And IEEE PFC/ETS is managed from ieee paths now instead
of using CEE primitives.

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>