crypto: caam - Remove bogus references to crypto API internals

The caam driver includes algorithm types that it doesn't even
use, such as struct rng_alg which has recently been moved to an
internal header file and consequently broke the build of caam.

This patch removes these bogus references.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>