dm-inlinecrypt: Expose inline crypto caps to the device

Add a new DM flag, which means the inline crypto capabilities
from underlying devices can be exposed to the DM device, and
the DM device consumes these capabilities, rather pass through
them to the upper layer.

Signed-off-by: Linlin Zhang <linlin.zhang@oss.qualcomm.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>