crypto: vmx - Convert to CPU feature based module autoloading

This patch utilises the GENERIC_CPU_AUTOPROBE infrastructure
to automatically load the vmx_crypto module if the CPU supports
it.

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>