STM32F1 USB cdc/msc composite device (#15180)

Co-Authored-By: bigtreetech <38851044+bigtreetech@users.noreply.github.com>

Marlin/src/HAL/HAL_STM32F1/msc_sd.h

@@ -0,0 +1,24 @@
+/**
+ * Marlin 3D Printer Firmware
+ *
+ * Copyright (c) 2019 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ * Copyright (c) 2019 BigTreeTech [https://github.com/bigtreetech]
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#pragma once
+
+#include <USBComposite.h>
+
+extern USBMassStorage MarlinMSC;
+extern USBCompositeSerial MarlinCompositeSerial;
+
+void MSC_SD_init();