Misaligned pointer update.

Created by: silabs-oysteink

Detecting misaligned pointers in the IF stage. Propagating alignment status down the pipeline and flagging exception code 0x0 if not ok.

Added assertions for checking that only mret pointers can cause misaligned instruction address exceptions. Added assertions to check that the alignment buffer only signal one valid for each pointer (currently failing), and that the alignment buffer must signal instr_valid_o if is not currently prefetching and the controller wants us to prefetch (currently failing).

The new and failing assertions will be addressed in a coming PR