Fix no-ec

Fix no-ec builds by having separate functions to create keys based on
an existing EVP_PKEY and a curve id.

Reviewed-by: Rich Salz <rsalz@openssl.org>
diff --git a/ssl/statem/statem_clnt.c b/ssl/statem/statem_clnt.c
index 6f4c8ff..338a23b 100644
--- a/ssl/statem/statem_clnt.c
+++ b/ssl/statem/statem_clnt.c
@@ -2250,7 +2250,7 @@
         SSLerr(SSL_F_TLS_CONSTRUCT_CKE_DHE, ERR_R_INTERNAL_ERROR);
         return 0;
     }
-    ckey = ssl_generate_pkey(skey, NID_undef);
+    ckey = ssl_generate_pkey(skey);
     dh_clnt = EVP_PKEY_get0_DH(ckey);
 
     if (dh_clnt == NULL || ssl_derive(s, ckey, skey) == 0) {
@@ -2288,7 +2288,7 @@
         return 0;
     }
 
-    ckey = ssl_generate_pkey(skey, NID_undef);
+    ckey = ssl_generate_pkey(skey);
 
     if (ssl_derive(s, ckey, skey) == 0) {
         SSLerr(SSL_F_TLS_CONSTRUCT_CKE_ECDHE, ERR_R_EVP_LIB);