staging: unisys: remove unused code from iochannel.h

The following macros and functions are unused, and should be deleted:

NUMSIGNALS
IO_CHANNEL_SIZE
QSLOTSFROMBYTES
QSIZEFROMBYTES
SignalQInit
INIT_CLIENTSTRING
ULTRA_IO_CHANNEL_SERVER_READY
ULTRA_IO_CHANNEL_SERVER_NOTREADY
ULTRA_VHBA_init_channel
ULTRA_VHBA_set_max
ULTRA_VNIC_init_channel

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