[rtl] Add common security features of regfiles to separate module

[aklsh]

Resolves #2217

[aklsh]

can someone with access to the private ci let me know what the fails are?

[marnovandermaas]

Thanks for your interest in the Ibex repository. In its current state this PR is a bit hard to review. First, please avoid making lots of white space changes. And if you do want to make a whole load of white space changes please separate them from the commits that have functional changes. Would you mind adding a comment in the common register file to say what functionality you've pulled out. And it would also be nice if you could put a short description in the pull request itself to describe what you've done and how what you've done still has the same functionality as before.

[aklsh]

I've tried resolving all the whitespace changes I had introduced unintentionally @marnovandermaas

And it would also be nice if you could put a short description in the pull request itself to describe what you've done and how what you've done still has the same functionality as before.

#2217 was opened to bring together common logic present in each of the three regfile implementations into one common module which can then be instantiated in each of the three implementations.

This PR mainly combines the security hardening logic that checks for onehot encoding in various signals for glitches in addresses and write enable(s). It tries to maintain the same logic as before wrt parameterization of these checks.