cxgbe(4): Move all control queues to the adapter.

There used to be one control queue per adapter (the mgmtq) that was
initialized during adapter init and one per port that was initialized
later during port init. This change moves all the control queues (one
per port/channel) to the adapter so that they are initialized during
adapter init and are available before any port is up. This allows the
driver to issue ctrlq work requests over any channel without having to
bring up any port.

MFH: 2 weeks
Sponsored by: Chelsio Communications