Optimize uhk80

[kareltucek]

@benedekkupper could you please:

• give me some hint on how to switch the zephyr build from -Os to -O3?
• maybe write some documentation of the build system when you have time?

rationale: uhk80 macro parser seems to run much slower on uhk80 than uhk60, causing absurd issues.

[benedekkupper]

You can navigate to https://github.com/zephyrproject-rtos/zephyr and talk to copilot to get answer to this kind of questions. For this specific topic, see SPEED_OPTIMIZATIONS kconfig value. The recommended location to set it is in prj_release.conf. I don't expect to see a big difference from SIZE_OPTIMIZATIONS though.

maybe write some documentation of the build system when you have time?

Can you elaborate a bit on this? What information do you need? Most of it would be links to zephyr and nrf SDK documentation.