* Add BOARD_VENDOR to board configs
* Add BOARD_VENDOR to all board configuration files
- Added BOARD_VENDOR variable to board configuration files
- Using lowercase vendor slugs (e.g., friendlyelec, radxa, xunlong)
- Set 'generic' for boards without clear vendor match
- TV box files (.tvb) excluded as they have no clear vendor
- Enables better board categorization and vendor-specific handling
* Manual adjustements on top of AI matching
* Drop doubled definition and add retroid vendor
* cleanup comments, linebreaks...
* two more comments
* `BOOTFS_TYPE` has never been set as far as I can see, therefore no need to unset.
* some more comments...
* comment, simplify logic
* even more comments
* just a few more
* comments, description for elish
* merge uboot functions. @SuperKali review
