0x1209: add 0xBB07 PID (BloomBoot)

[pietrmar]

This adds a new PID for the BloomBoot (https://github.com/pietrmar/bloomboot) bootloader which is a simple UF2/DFU capable bootloader, currently only supporting the nrf52840/theadmouse device, but which can later be extended.

MIT licensed.

[tannewt]

MIT C source. Third party hardware.

[tannewt]

Are you aware of https://github.com/adafruit/Adafruit_nRF52_Bootloader and https://github.com/adafruit/tinyuf2?

[pietrmar]

Hi, thank you for merging the pull request.

Yes I'm aware of the Adafruit nRF52 Bootloader, but I decided not to use it because it requires the Nordic "soft device" binary blob for some BLE features and other things that I do not require, but which blow up the parition size.
Additionally I have my custom partition layout and partition management, I wanted DFU support and also the bootloader to be nicely relocatable into RAM.

On top of that I was not happy with the code quality and size for the Adafruit nrf52 bootloader, to me it looks like a proof of concept that was never really cleaned up. So that was my decision to give it a shot with the TinyUSB library (anyway from Adafruit) and the ghostfat.c module from the TinyUF2 bootloader.

I could have probably added nrf52 support to TinyUF2 but I think the amount of effort would have been similar and I prefer to have code in my own style anyway.

Also just for completeness, the hardware itself is also open and CERN-OHL-S licensed.