stmhal: USB CDC and MSC device work together.

stmhal/Makefile

stmhal/main.c

stmhal/usb.c

stmhal/usbd_conf.c

stmhal/usbd_desc_cdc_msc.c

stmhal/usbd_msc_storage.c

stmhal/usbdev/class/cdc_msc/inc/usbd_cdc_msc.h

stmhal/usbdev/class/cdc_msc/inc/usbd_msc_bot.h

stmhal/usbdev/class/cdc_msc/inc/usbd_msc_data.h

stmhal/usbdev/class/cdc_msc/inc/usbd_msc_scsi.h

stmhal/usbdev/class/cdc_msc/src/usbd_cdc_msc.c

stmhal/usbdev/class/cdc_msc/src/usbd_msc.c

stmhal/usbdev/class/cdc_msc/src/usbd_msc_bot.c

stmhal/usbdev/class/cdc_msc/src/usbd_msc_data.c

stmhal/usbdev/class/cdc_msc/src/usbd_msc_scsi.c