Don't extend support for deprecated functions

Restore guards from the previous release, instead of the new, more
permissive guards.

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h
index d6083da..debb1cc 100644
--- a/include/mbedtls/ssl.h
+++ b/include/mbedtls/ssl.h
@@ -1503,7 +1503,7 @@
     const uint16_t *MBEDTLS_PRIVATE(sig_algs);      /*!< allowed signature algorithms       */
 #endif /* MBEDTLS_SSL_HANDSHAKE_WITH_CERT_ENABLED */
 
-#if defined(MBEDTLS_PK_HAVE_ECC_KEYS) && !defined(MBEDTLS_DEPRECATED_REMOVED)
+#if defined(MBEDTLS_ECP_C) && !defined(MBEDTLS_DEPRECATED_REMOVED)
     const mbedtls_ecp_group_id *MBEDTLS_PRIVATE(curve_list); /*!< allowed curves             */
 #endif
 
@@ -3651,7 +3651,7 @@
                                      unsigned int bitlen);
 #endif /* MBEDTLS_DHM_C && MBEDTLS_SSL_CLI_C */
 
-#if defined(MBEDTLS_PK_HAVE_ECC_KEYS)
+#if defined(MBEDTLS_ECP_C)
 #if !defined(MBEDTLS_DEPRECATED_REMOVED)
 /**
  * \brief          Set the allowed curves in order of preference.
@@ -3697,7 +3697,7 @@
 void MBEDTLS_DEPRECATED mbedtls_ssl_conf_curves(mbedtls_ssl_config *conf,
                                                 const mbedtls_ecp_group_id *curves);
 #endif /* MBEDTLS_DEPRECATED_REMOVED */
-#endif /* MBEDTLS_PK_HAVE_ECC_KEYS */
+#endif /* MBEDTLS_ECP_C */
 
 /**
  * \brief          Set the allowed groups in order of preference.