s390/dasd: add query PPRC function

[ Upstream commit 3f217cce ]

Add function to query the Peer-to-Peer-Remote-Copy (PPRC) state of a
device by reading the related structure through a read subsystem data call.

Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com>
Link: https://lore.kernel.org/r/20220920192616.808070-3-sth@linux.ibm.com


Signed-off-by: Jens Axboe <axboe@kernel.dk>
Stable-dep-of: c3116e62 ("s390/dasd: fix double module refcount decrement")
Signed-off-by: Sasha Levin <sashal@kernel.org>