Change restart context type.

No need to have both x509 and ecdsa, as the former contains the later.
diff --git a/include/mbedtls/ssl_internal.h b/include/mbedtls/ssl_internal.h
index bc38b8b..00a8db4 100644
--- a/include/mbedtls/ssl_internal.h
+++ b/include/mbedtls/ssl_internal.h
@@ -228,7 +228,7 @@
 #endif /* MBEDTLS_X509_CRT_PARSE_C */
 #if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
     int ecrs_enabled;                   /*!< Handshake supports EC restart? */
-    mbedtls_ecdsa_restart_ctx ecrs_ctx; /*!< ECDSA restart context          */
+    mbedtls_x509_crt_restart_ctx ecrs_ctx;  /*!< restart context            */
     enum {
         ssl_ecrs_init = 0,              /*!< just getting started           */
         ssl_ecrs_ske_read,              /*!< ServerKeyExchange was read     */