bfq: Re-enable auto-loading when built as a module

The block core requests modules with the "-iosched" name suffix, but
bfq no longer has that suffix.  Add an alias.

Fixes: ea25da4808 ("block, bfq: split bfq-iosched.c into multiple ...")
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/bfq-iosched.c

@@ -5013,6 +5013,7 @@ static struct elevator_type iosched_bfq_mq = {
 	.elevator_name =	"bfq",
 	.elevator_owner =	THIS_MODULE,
 };
+MODULE_ALIAS("bfq-iosched");
 
 static int __init bfq_init(void)
 {