Feature: NXP MCXN947 support

[wiboticalex]

Detailed description

This pull request implements support for the NXP MCXN947 microcontroller. It builds upon the lpc55xx target as the chips seem to work in a similar way.

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 (see Building the firmware)
• It builds as BMDA (see Building the BMDA)
• 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

[wiboticalex]

I also found #2095 relates to the segfault that I worked around. I don't think there's any harm allocating the extra space in lpc55xx, but thought I'd point it out.

[dragonmux]

This seems reasonable, so we'll get this merged when the v2.1 merge window opens. We may well ask you to rebase this PR at that point for a clean merge.