ssl_tls: fix proper guards for accelerated ECDH

Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index a9c7005..cf46c2b 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -4224,7 +4224,7 @@
     if (handshake->ecdh_psa_privkey_is_external == 0) {
         psa_destroy_key(handshake->ecdh_psa_privkey);
     }
-#endif /* MBEDTLS_ECDH_C && MBEDTLS_USE_PSA_CRYPTO */
+#endif /* MBEDTLS_PK_CAN_ECDH && MBEDTLS_USE_PSA_CRYPTO */
 
 #if defined(MBEDTLS_SSL_PROTO_TLS1_3)
     mbedtls_ssl_transform_free(handshake->transform_handshake);