crypto: marvell - Don't overwrite default creq->state during initialization

Currently, in mv_cesa_{md5,sha1,sha256}_init creq->state is initialized
before the call to mv_cesa_ahash_init. This is wrong because this
function fills creq with zero by using memset, so its 'state' that
contains the default DIGEST is overwritten. This commit fixes the issue
by initializing creq->state just after the call to mv_cesa_ahash_init.

Fixes: commit b0ef5106 ("crypto: marvell/cesa - initialize hash...")
Signed-off-by: Romain Perier <romain.perier@free-electrons.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>