kingst-la2016: complete hardware setup in probe, set features in open

kingst-la2016: complete hardware setup in probe, set features in open

Complete all of the MCU firmware load, device type identification, FPGA
bitstream load, and FPGA initialization by the end of scan(). This gives
an easily usable device of known capabilities for the remaining driver
lifetime, which just needs to get opened by connection ID (which was
retrieved during scan).

I still don't like how the driver's open() configures PWM without user
provided specs. And enforcing the logic threshold is redundant before
acquisition start. This needs more attention later.