Enable updates of kernel on all, change keywords

[igorpecovnik]

Description

Kernel switching condition was wrongly set to only allow this to supported distributions. Which makes no sense. Kernel switching should be enable for all variants.

Also changing keywords to some logical human understandable variants.

Testing Procedure

armbian-config --cmd STABLE
armbian-config --cmd ROLLING

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have ensured that my changes do not introduce new warnings or errors
• No new external dependencies are included
• Changes have been tested and verified
• I have included necessary metadata in the code, including associative arrays

[Tearran]

How many of these "SHORT CUTS" will we need? can start with some manual entries perhaps something like

[[ "$FIRMWARE" == "stable" || "$FIRMWARE" == "rolling" ]] && { module_armbian_firmware repository "$FIRMWARE" ; exit }

FIRMWARE="Stable" ./bin/armbian-config --api

    "--api")
...
            "help")
                see_use
                ;;
            "")
                [[ "$FIRMWARE" == "stable" || "$FIRMWARE" == "rolling" ]] && module_armbian_firmware repository "$FIRMWARE"
...

[igorpecovnik]

This was more for the user side part - that menu entry has something logical instead of SY1234 / SY1235.