crypto: arm/curve25519 - add arch-specific key generation function

Somehow this was forgotten when Zinc was being split into oddly shaped
pieces, resulting in linker errors. The x86_64 glue has a specific key
generation implementation, but the Arm one does not. However, it can
still receive the NEON speedups by calling the ordinary DH function
using the base point.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

arch/arm/crypto/curve25519-glue.c

@@ -38,6 +38,13 @@ void curve25519_arch(u8 out[CURVE25519_KEY_SIZE],
 }
 EXPORT_SYMBOL(curve25519_arch);
 
+void curve25519_base_arch(u8 pub[CURVE25519_KEY_SIZE],
+			  const u8 secret[CURVE25519_KEY_SIZE])
+{
+	return curve25519_arch(pub, secret, curve25519_base_point);
+}
+EXPORT_SYMBOL(curve25519_base_arch);
+
 static int curve25519_set_secret(struct crypto_kpp *tfm, const void *buf,
 				 unsigned int len)
 {