feat(uart): update uart driver for esp32s2beta

components/soc/esp32/include/soc/uart_caps.h

@@ -0,0 +1,26 @@
+// Copyright 2017-2018 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+#ifndef _SOC_UART_CAPS_H_
+#define _SOC_UART_CAPS_H_
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define SOC_UART_NUM  3
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  /* _SOC_UART_CAPS_H_ */