dm: allow bio-based table to be upgraded to bio-based with DAX support

Allow table type DM_TYPE_BIO_BASED to extend with DM_TYPE_DAX_BIO_BASED
since DM_TYPE_DAX_BIO_BASED supports bio-based requests.

This is needed to allow a snapshot of an LV with DAX support to be
removed.  One of the intermediate table reloads that lvm2 does switches
from DM_TYPE_BIO_BASED to DM_TYPE_DAX_BIO_BASED.  No known reason to
disallow this so...

Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>