main/devicepkg-dev: Automatically install initfs-hook.sh
We have a lot of device packages that have an initfs hook so it make sense for devicepkg_package to take care of it automatically.
The following devices have an initfs hook but don't use devicepkg-dev (#8 (closed)) so they are left unchanged:
- htc-ace
- htc-bravo
- lg-d285
- lg-lenok
- motorola-osprey
- nokia-n9
- ouya-ouya