crypto: starfive - remove unneeded crypto_engine_stop() call

The explicit crypto_engine_stop() call is not needed, as it is already
called internally by crypto_engine_exit().

Signed-off-by: Ovidiu Panait <ovidiu.panait.oss@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>