hdr10plus: decouple the src from hdr10plus_tool
The main reason for this is cargo-c latest version is not available in master yet.
This will need to be reverted in staging once https://github.com/NixOS/nixpkgs/pull/413726 is merged
Signed-off-by: John Titor <50095635+JohnRTitor@users.noreply.github.com>