staging: unisys: refactor ULTRA_DIAG_CHANNEL_PROTOCOL

Get rid of the typedef and use struct spar_diag_channel_protocol instead. Fix
CamelCase member names, and update references and comments to match.

struct channel_header CommonChannelHeader;
QueueHeader => queue_header
DiagChannelHeader => diag_channel_header
Events => events

Signed-off-by: Benjamin Romer <benjamin.romer@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>