crypto: caam - RNG instantiation by directly programming DECO

Remove the dependency of RNG instantiation on Job Ring. Now
RNG instantiation for devices with RNG version > 4 is done
by directly programming DECO 0.

Signed-off-by: Ruchika Gupta <ruchika.gupta@freescale.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>