Debug triggers refactor

Created by: silabs-oysteink

Moved all trigger related code to a new module - debug_triggers.sv. CSR decoding is still done in cs_registers, but the actual CSR instances for trigger CSRs are moved to the new submodule. Trigger matches (instruction address only) is done in this new module.

This is the first step towards configurable number of triggers and the addition of new trigger types.

SEC clean

Do not merge until PR #696 is merged. This is to make the merge to cv32e40s easier.

Signed-off-by: Oystein Knauserud Oystein.Knauserud@silabs.com