crypto: tcrypt - reschedule during speed tests

Avoid RCU stalls in the case of non-preemptible kernel and lengthy
speed tests by rescheduling when advancing from one block size
to another.

Signed-off-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>