boards: Add support for PG23/PG28 Pro Kit

[janchri]

This PR adds support for two development kits from Silicon Labs:

• PG23-PK2504A
• PG28-PK2506A

For the PG23-PK2504A, RTT has been configured due to issues when accessing the console via EUSART0/1. Tested manually on basic samples (hello world, blinky, and button).

This PR builds on the work carried out for xg24_ek2703a and other ports from the dev Kit folder.

Depends on: zephyrproject-rtos/hal_silabs#95

[github-actions]

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[github-actions]

The following west manifest projects have changed revision in this Pull Request:

Name	Old Revision	New Revision	Diff
hal_silabs	zephyrproject-rtos/hal_silabs@190a144	zephyrproject-rtos/hal_silabs@95e9574 (main)	zephyrproject-rtos/[email protected]

✅ All manifest checks OK

Note: This message is automatically posted and updated by the Manifest GitHub Action.

[janchri]

Thank a lot for the feedback @asmellby

[asmellby]

Documentation build fails due to lack of indentation here, same for pg28.

[asmellby]

I don't think your latest change did what you wanted it to:

While the error message complained about a missing newline, indentation was also missing to make the options part of the code block.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
7.1% Duplication on New Code

See analysis details on SonarQube Cloud

[nordicjm]

think this can go @kartben ?

[kartben]

Yes, please, the board "card" summary already conveniently links to the board's source folder on GitHub where folks can easily find defconfig files

[github-actions]

Hi @janchri!
Congratulations on getting your very first Zephyr pull request merged 🎉🥳. This is a fantastic achievement, and we're thrilled to have you as part of our community!

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Thank you for your valuable input, and we look forward to seeing more of your contributions in the future! 🪁