Use the Ed25519 base smul in Curve25519 base mul and covert to
Montogmery curve for a faster implementation.
Only when Ed25519 is compiled in or WOLFSSL_CURVE25519_USE_ED25519 is
defined.
When compiling Intel x64 assembly and Aarch64 assembly, always define
WOLFSSL_CURVE25519_USE_ED25519.
Can't use with blinding - normal C implementation.
Optimized the Curve25519 smul slightly for Intel x64 and Aarch64.
Improved the conditional table lookup on Intel x64 to use AVX2 when
available.
Sean Parkinson
f54266c2c6