crypto: sun8i-ce - remove channel timeout field

Using the number of bytes in the request as DMA timeout is really
inconsistent, as large requests could possibly set a timeout of
hundreds of seconds.

Remove the per-channel timeout field and use a single, static DMA
timeout of 3 seconds for all requests.

Signed-off-by: Ovidiu Panait <ovidiu.panait.oss@gmail.com>
Tested-by: Corentin LABBE <clabbe.montjoie@gmail.com>
Reviewed-by: Corentin LABBE <clabbe.montjoie@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>