Stm32u5 support

[jcamdr]

Detailed description

Addition of the documentation reference for the STM32U5.
Addition of the DP_TARGETIDR id for the STM32U5.
Addition of the stm32l4_device_info for the STM32U5.
Addition of the RAM map for the STM32U5.

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]

This is looking great, there's just one tweak that needs making and when done we can then merge this. Thank you for the contribution!

[jcamdr]

I will agree if you ask me to integrate the change request into the second commit. I was not so confident that the operation proposed by the github interface will do that or not.

[dragonmux]

Yes, please do - sorry, meant to get back to this PR earlier and ask you to do just that. With that change made part of the second commit, we're happy to mark as accepted and merge this

[jcamdr]

Don't worry, it's part of the normal learning curve for working together.

[dragonmux]

LGTM now, merging.

[jcamdr]

Thank you!
I will now think about the flash, the biggest part.