Add mtopi CSR

[KushalMeghani1644]

This PR reintroduces the mtopi CSR addition from my previous PRs (#347 and #359),
but from a clean branch as suggested by the reviewers.
The diff is identical to the intended changes; commit history has been cleaned up.

[romancardenas]

Thanks! Just a few changes: add the field check in the new macro to check the field bit range and use hex representation in a test.

[KushalMeghani1644]

I feel like this CI failing again, isn't the fault of the code changes made in this PR, the spellings were definitely not changed by me, I can & will fix this, but it's quiet late in my timezone... and as for the lints, same condition there, I'll fix them :)

[romancardenas]

Hi @KushalMeghani1644

Don't worry about CI now, I will try to have it working ASAP (Nightly clippy triggers new errors from time to time). The checks that fail are not blockers for merging.

Please, address the comment about the tests and it is good to go.

[KushalMeghani1644]

Hi @KushalMeghani1644

Don't worry about CI now, I will try to have it working ASAP (Nightly clippy triggers new errors from time to time). The checks that fail are not blockers for merging.

Please, address the comment about the tests and it is good to go.

Fine! I have updated the test_ro_csr_field to validated start and end by masking the expected range and comparing against raw bits and the field value. I hope the changes are fine... :)

[romancardenas]

Thanks! Minor changes

[KushalMeghani1644]

Thanks! @romancardenas for giving the review + commits, I have applied them, if there's any other change I'll happily make them :)

[romancardenas]

LGTM