crypto: caam - Check for CAAM block presence before registering with crypto layer

The layer which registers with the crypto API should check for the presence of
the CAAM device it is going to use.  If the platform's device tree doesn't have
the required CAAM node, the layer should return an error and not register the
algorithms with crypto API layer.

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