boards: silabs: Add support for xg22_ek2710a board, additional xG22 SoCs

[loopj]

This PR adds support for:

• Silicon Labs EFR32MG22 SoCs
• Additional EFR32BG22 SoCs
• The EFR32xG22E Explorer Kit board (BRD2710A / xG22-EK2710A)

Depends on zephyrproject-rtos/hal_silabs#116

[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 (main)	zephyrproject-rtos/hal_silabs#116	zephyrproject-rtos/hal_silabs#116/files

⛔ DNM label due to: 1 project with PR revision

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

[Martinhoff-maker]

Thanks for this addition @loopj!
For me, this PR is already really nice. I only have a few comments/clarifications.
Make sure to add commit bodies to all of your commits as required by the Zephyr contribution guidelines (https://docs.zephyrproject.org/latest/contribute/guidelines.html#commit-message-guidelines).
Additionally, in the first commit, I would suggest splitting the entropy driver changes into a separate commit.

[loopj]

Thanks for the quick reviews @Martinhoff-maker, @nordicjm!

I think I've addressed all review comments, let me know if I missed anything.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

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

See analysis details on SonarQube Cloud