Increase max. devices per type

[elral]

Is your feature request related to a problem? Please describe.
For now each board has a limitation of max devices per type. In the meantime the firmware does not have this limitation anymore, so depending on available pins per Board and considering limitations from the used libraries the current limitation can be increased.

Describe the solution you'd like
Adapt the board.json files, increase the max. number of devices per type.

Describe alternatives you've considered
None.

Additional context
See also explanations/calculations which have be done in PR MobiFlight/MobiFlight-FirmwareSource#253