samsung-lt01: create common device package for all variants, use the mainline kernel

Quick rundown of this MR:

• Upgrade the Exynos 4 kernel to 6.5.1 (WIP - needs tag after https://gitlab.com/exynos4-mainline/linux/-/merge_requests/4). This could be split off into a separate MR. Update has been done separately. There's a commit to add patch https://gitlab.com/exynos4-mainline/linux/-/merge_requests/13 which hasn't been merged yet.
• Expand the firmware-samsung-midas package to add lt01 NVRAM TXTs
• Move old downstream package to unmaintained
• Add a new shared device package for all lt01 variants that uses the mainline kernel.

samsung-lt01wifi is renamed to samsung-lt01. I'd appreciate some feedback on how the move is handled; should I start counting the new package's versions from 0.1, or is starting at 1.0 acceptable (given how this is an evolution of the old device-samsung-lt01wifi package)? Is the handling of the different variants acceptable, or should it be done differently (separate device packages)?