Prepare for adding code that will query the I/O advice hints group
descriptors and for adding code that will retrieve the stream status.

Cc: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240130214911.1863909-11-bvanassche@acm.orgSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>