ixgbe: Make ixgbe_setup_tc usable even when DCB is not enabled

The ixgbe_setup_tc code is essentially the same code we need any time we have
to update the number of queues.  As such I am making it available always and
just stripping the DCB specific bits out when DCB is disabled instead of
stripping the entire function.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Reviewed-by: John Fastabend <john.r.fastabend@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>