elfutils: bump version to 0.161

elfutils: bump version to 0.161

- Bump version to 0.161
- Remove the portability patch. We don't need to have it in Buildroot
  since it includes the version number so we can download it safely
  without having collisions between versions.
- Adapt the patches that need to be adapted.
- Rename patches to start from 0001.
- Update the hash value and add a new value for the portability patch.

Signed-off-by: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>