[S390] css: move io_private to drv_data

Use the subchannels drv_data to access io_subchannel_private
for io subchannels.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2 files changed