- define CIRCUITPY_BUILD_EXTENSIONS to predefined values
- set CIRCUITPY_BUILD_EXTENSIONS in port and board config
- reuse the support matrix "get_settings_from_makefile" to get it
- move the existing port and board specific values
- remove the C3 specific board values because it's not the default
- update build_release_files.py to use get_settings_from_makefile
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.
Neradoc
Jeff Epler
Scott Shawcroft
Dan Halbert
Josh Klar