Make release for afmhf

[larstobi]

Please make a release for armhf (UDOO Quad) so that installing the board with Arduino works.

I'm using this https://github.com/arduino/arduino-cli

When trying to install it, I get this message:

root@udoo:~/.arduino15# arduino-cli core install UDOO:sam
Tool arduino:arm-none-eabi-gcc@4.8.3-2014q1 already installed
The tool UDOO:bossac-udoo@1.3a-1.0 is not available for the current OS

However, there is commited a prebuilt binary:

https://github.com/UDOOboard/bossac/blob/master/prebuilt/udoo/bossac-udoo