This started while adding USB MIDI support (and descriptor support is
in this change.) When seeing that I'd have to implement the MIDI class
logic twice, once for atmel-samd and once for nrf, I decided to refactor
the USB stack so its shared across ports. This has led to a number of
changes that remove items from the ports folder and move them into
supervisor.
Furthermore, we had external SPI flash support for nrf pending so I
factored out the connection between the usb stack and the flash API as
well. This PR also includes the QSPI support for nRF.
Some boards (like the uGame10) may want to have their own set of extra
modules. This change lets them override EXTRA_BUILTIN_MODULES in their
mpconfigboard.h and makes the ugame10 board do that.
There have been multiple uGame prototypes with differences in the pins
and other details. This updates the board definition to fit the final
uGame 10 design.
