s390x/css: Add passthrough IRB

Wire in the subchannel callback for building the IRB
ESW and ECW space for passthrough devices, and copy
the hardware's ESW into the IRB we are building.

If the hardware presented concurrent sense, then copy
that sense data into the IRB's ECW space.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
Message-Id: <20210617232537.1337506-5-farman@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
4 files changed