[SCSI] zfcp: Move WKA port to zfcp FC code

The well-known-address (WKA) port handling code is part of the FC code
in zfcp. Move everything WKA related to the zfcp_fc files and use the
common zfcp_fc prefix for structs and functions. Drop the unused key
management service while renaming the struct, no request could ever
reach this service in zfcp and it is obsolete anyway.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>