dm raid: bump target version

Bumo dm-raid target version to 1.12.1 to reflect that commit cc27b0c7
("md: fix deadlock between mddev_suspend() and md_write_start()") is
available.

This version change allows userspace to detect that MD fix is available.

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>