cxgb4 : Allow firmware DCB info to be queried in host state

Since finally DCB traffic management is still handled by firmware,
allow firmware to be fully programmed and queried even in host
managed state for the cases where this was previously rejected.

Signed-off-by: Anish Bhatt <anish@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>