dt-bindings: crypto: Add Keem Bay ECC bindings

Add Keem Bay Offload and Crypto Subsystem (OCS) Elliptic Curve
Cryptography (ECC) device tree bindings.

Signed-off-by: Prabhjot Khurana <prabhjot.khurana@intel.com>
Signed-off-by: Daniele Alessandrelli <daniele.alessandrelli@intel.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>