adding tuh_cdc_mount_cb/tuh_cdc_umount_cb

start adding cdc_app.c to example

examples/host/cdc_msc_hid/src/cdc_app.c

@@ -0,0 +1,51 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2022, Ha Thach (tinyusb.org)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * This file is part of the TinyUSB stack.
+ */
+
+#include "tusb.h"
+
+//--------------------------------------------------------------------+
+// MACRO TYPEDEF CONSTANT ENUM DECLARATION
+//--------------------------------------------------------------------+
+
+
+//------------- IMPLEMENTATION -------------//
+
+void cdc_app_task(void)
+{
+
+}
+
+void tuh_cdc_mount_cb(uint8_t dev_addr)
+{
+  (void) dev_addr;
+  printf("A CDC device is mounted\r\n");
+}
+
+void tuh_cdc_umount_cb(uint8_t dev_addr)
+{
+  (void) dev_addr;
+  printf("A CDC device is unmounted\r\n");
+}