cipher:ecc: Add _gcry_ecc_curve_mul_point function with curve name.
* cipher/ecc-ecdh.c (_gcry_ecc_curve_mul_point): New. Also support Weierstrass curve as well as Montgomery one. (_gcry_ecc_mul_point): Use _gcry_ecc_curve_mul_point.
- Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>