Make LEC flow

Created by: Silabs-ArjanB

The 'Core Versions and RTL Freeze Rules' described in https://core-v-docs-verif-strat.readthedocs.io/projects/cv32e40p_um/en/latest/core_versions.html rely on using LEC for commits to the CV32E40P repos after RTL freeze.

Such a LEC flow needs to be set up and should be easy to run for new commits.