[Coding Convention] Cleaning

- Rename functions, consts, types according to new prefix dls_ or DLS_
- Harmonize header files
     -> Same definition/usage for the header inclusion protection.
     -> Same presentation
- Same project name (dleyna -> dLeyna)
- Check copyright
- Run checkpatch

Signed-off-by: Ludovic Ferrandis <ludovic.ferrandis@intel.com>