crypto: caam - add support for iMX6UL

i.MX6UL does only require three clocks to enable CAAM module.

Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>