[S390] dasd: check if raw track access is supported

To use raw track access some special storage server commands are
needed. Older storage hardware may not support these commands.
So check if raw track access is possible while setting the DASD
online.

Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>