s390/qdio: use dev_info() in qdio_print_subchannel_info()

Prefer dev_info() over a raw printk. This also adds the device and
driver names into the output, so that we have:

Before:
    qdio: 0.0.17c0 ZFCP on SC 17 using [...]

After:
    zfcp 0.0.17c0: qdio: ZFCP on SC 17 using [...]

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>