USBDevice for STM support

Dependents:   Nucleo_Usb_JoyMouse Nucleo_usbmouse ELEC350_1-referral-2018-usb-hid USBJoystick_HelloWorld2_wip ... more

This library contains all mbed usb device library (mbed-os\features\unsupported\USBDevice).

readme.txt/shortlog/shortlog@50ec00aa4515: not found in manifest