Update I2S driver for esp32s2beta.

components/soc/esp32/include/soc/i2s_caps.h

@@ -0,0 +1,18 @@
+// Copyright 2015-2019 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.
+
+#pragma once
+
+#define SOC_I2S_PERIPH_NUM      (2) //ESP32 have 2 I2S
+#define SOC_I2S_SUPPORT_PDM     (1) //ESP32 support PDM