The readme reports the wrong licences for libusb

Hello,
the readme says that libusb is licensed under GPLv2, but it's LGPLv2.1

> **[License](https://github.com/pyocd/libusb-package#license)**
> The Python code for libusb-package is licensed with Apache 2.0.
> The libusb library and its source code are licensed with GPLv2.

here is [libusb license](https://github.com/libusb/libusb/blob/master/COPYING)