staging: unisys: refactor VISORCHIPSET_EXTERNALPORT_INFO

Remove the typedef and just use struct visorchipset_externalport_info instead.
Fix all CamelCase names:

switchNo => switch_no
externalPortNo => external_port_no
networkZoneGuid => network_zone_uuid
pdPort => pd_port
ipNetmask => ip_netmask
ipBroadcast => ip_broadcast
ipNetwork => ip_network
ipGateway => ip_gateway
ipDNS => ip_dns
Reserved1 => reserved1
Reserved2 => reserved2
pendingMsgHdr => pending_msg_hdr

Signed-off-by: Benjamin Romer <benjamin.romer@unisys.com>