dslogic: Implement trigger functionality

dslogic: Implement trigger functionality

This commit implements DSLogic trigger functionality.

The following triggers are working:

 - trigger on rising edge
 - trigger on falling edge
 - trigger on any edge
 - trigger on logic one
 - trigger on logic zero

Pre-trigger capture ratio is also working.

Signed-off-by: Diego Asanza <redacted>
Tested-by: Andrew Bradford <redacted>