goodixmoc: support for clear_storage

The internal storage of this device can get messed up by other operating systems, so it's handy to be able to clear it.

I'm not 100% sure whether the commands I've sent to the device are exactly what is supposed to be used (just a guess), but it did seem to work, and it even fixed another issue I had.

I can confirm that this causes zero issues with either Windows or Linux, and even fixes some anomalous behavior that can happen when switching between the two. For example, I had an issue where after enrolling a lot of fingerprints on Windows, every fingerprint I enrolled on Linux was exactly the same no matter what it was, but then it couldn't see the Windows data to delete it (but why, I'm still not sure)

In any case, clear_storage as implemented here can fix those kinds of issues and restore the device to factory working order.