Adds NXP 6.12 support to the i.MX93 image

[swegener-rtp]

Summary

Adds experimental support for the NXP 6.12.34-2.1.0 BSP on the FRDM-i.MX93 while keeping NXP 6.6.52-2.2.2 as the default release.

Changes

• Added the NXP 6.12 release profile and required Walnascar metadata
• Added the NXP 6.12 kernel and U-Boot configuration
• Updated TensorFlow Lite and Ethos-U support for the 6.12 release
• Added required meta-clang and meta-security layers
• Updated image and systemd integration for the newer Yocto release
• Added systemd-analyze to the development image
• Minor layout update to geisa-system-state script

Validation Done

• NXP 6.6 release-profile validation and parse passed
• Full NXP 6.12 geisa-dev-image build passed
• Final image records a clean source state at b8c5e063c89d4fc8b8654e825850ab7d622a6d28
• Boot validated from SD and eMMC on FRDM-i.MX93
• No failed systemd units
• systemd-analyze and geisa-system-state --once validated
• Ethos-U hardware smoke test passed with TensorFlow Lite 2.19.0

Final image SHA-256:

ae34d0d6ac3e84c13bbb00b1d191b20655edf24c684d566eadf06c18c899efd2