crypto: curve25519 - implement generic KPP driver

Expose the generic Curve25519 library via the crypto API KPP interface.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/Kconfig b/crypto/Kconfig
index 64cc4a9..fab259d 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -264,6 +264,11 @@
 	  standard algorithms (called GOST algorithms). Only signature verification
 	  is implemented.
 
+config CRYPTO_CURVE25519
+	tristate "Curve25519 algorithm"
+	select CRYPTO_KPP
+	select CRYPTO_LIB_CURVE25519_GENERIC
+
 comment "Authenticated Encryption with Associated Data"
 
 config CRYPTO_CCM