Fix Todo: Remove Todo comments in id_stage.sv

Created by: silabs-PaulZ

Remove two TODOs in the cv32e40p_id_stage.sv RTL based on issue #430 (closed)

Both TODO comments added by @atraber , 5 years back.

The first comment refers to optimizing the code to possibly reuse bit-manipulation logic to perform the custom clipping for XPULP instructions. At this stage, this level of optimization is not needed.

The second comment refers to optimizing immediate_b_mux sign extension, most likely applying to the custom XPULP instruction formats. @atraber, Please review this PR to remove those comments.

Signed-off-by: Paul Zavalney paul.zavalney@silabs.com