crypto: amcc - switch to AES library for GCM key derivation

The AMCC code for GCM key derivation allocates a AES cipher to
perform a single block encryption. So let's switch to the new
and more lightweight AES library instead.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>