Move atmel-samd to tinyusb and support nRF flash.

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.

1 files changed, 0 insertions, 0 deletions

diff --git a/ports/atmel-samd/peripherals b/ports/atmel-samd/peripherals
-Subproject d0dcba251c27f629c0a89b5ced4433dd0a609ca
+Subproject f20fcf642b5654ee68d7d551ea7db39716ef83b