ioengines: add helper for trims with async ioengines

ioengines: add helper for trims with async ioengines

Async ioengines support trim commands but trims are synchronous
operations. We need to provide special handling when measuring latency
for these commands. Create a helper function to help us identify when an
async ioengine is issuing a sync trim command. This makes the code more
readable.

Signed-off-by: Vincent Fu <vincent.fu@samsung.com>
Link: https://lore.kernel.org/r/20220614155822.307771-2-vincent.fu@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>