[BLO-V2] Add protection for blocking output stage
With a wrong firmware downloaded to the FPGA, the blocking output stage can be destroyed by forcing a logic HIGH on the FPGA output. Continuously turning on the controlling MOSFET would create a high current which burns up this transistor. Since one FPGA output drives three blocking outputs (three outputs per channel), this issue extends to three burnt transistors.
The issue should be solved as part of V3 boards by implementing a protection circuit.