ctl: Add NVMF port type and ioctls

[jhb]

Summary

• Add CTL_PORT_NVMF as a new port type.

• Define a new CTL_NVMF ioctl for NVMF-specific operations similar to CTL_ISCSI. This ioctl supports a command to handoff a single queue pair, a command to enumerate active associations, and a command to disconnect one or more active associations.

Sponsored by: Chelsio Communications