Support for TI MSP432E4 parts

[neutered]

Detailed description

add the ti msp432e4 variant. they're both arm cortex-m4f cores but the rest of the internals are pretty different so it was suggested (dragonmux on discord) that a new target was probably the best way to go.

Your checklist for this pull request

• I've read the Code of Conduct
• I've read the guidelines for contributing to this repository
• It builds for hardware native (make PROBE_HOST=native)
• It builds as BMDA (make PROBE_HOST=hosted)
• I've tested it to the best of my ability
• My commit messages provide a useful short description of what the commits do

Closing issues

[dragonmux]

Thank you for the contribution! We've quickly edited the description to remove the spaces that were preventing the checkboxes being parsed correctly.

One thing of note before we do a code review: please correct the commit messages for all 3 commits to provide what target each modifies - for example msp432p4: Shuffle the MSP432 code about and msp432e4: Implement support for the MSP432E4 variant. The reason for asking for this is so, later, when we're trying to review commit history for building release notes or if we need to bisect, blame, or otherwise inspect the commit log, we get a clear view of what each commit touches and a fair idea of how

[neutered]

sorry, i missed the mail yesteray when i was wfh-ing. it might be a day or two.

[neutered]

i think i did the subject-line change, but force pushed since no one else was on this branch. github seems ok w/ it, but how this interacts w/ the pull request proper remains to be seen.

please take a look?

[dragonmux]

Looks fine - the only pre-merge issue that stands now is that you need to update your branch against main - but we'd hold off on this till fix/naming-conformity has merged otherwise you'll keep having to re-do work. If push comes to shove, with your permission, we are able to update the branch for you to resolve the merge conflict.

The quick and easy way to update against main, assuming you have the main repo as a remote named usptream is to run this sequence:

git switch main
git pull upstream main
git switch pull-ti-msp432e4
git rebase main
git push -f

[dragonmux]

Please can you rebase this on main, or let us know if you're ok with us doing so, so we can get this merged?

[dragonmux]

Given the time between asking for this to be rebased and now, we're going to get on and do so. Getting this sorted out and merged for v1.10 would be really good.

[dragonmux]

We have now adjusted the attribution as the new support had an incomplete copyright notice. We have also performed some refinement on the new support to reduce added Flash usage and integrate it with the existing framework and naming schemes better.

We're happy for this to be merged, so it's over to Esden for a review with a view to merge.

[perigoso]

The flash routines look great now :) they are at the simplicity level I would like to see on all targets! (It's on my todo to optimize some)

[esden]

LGTM!