Of the two versions of GHASH that the ARM driver implements, only one
performs aggregation, and so the other one has no use for the powers
of H to be precomputed, or space to be allocated for them in the key
struct. So make the context size dependent on which version is being
selected, and while at it, use a static key to carry this decision,
and get rid of the function pointer.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>