at: bump version to 3.1.16

- Bump version to 3.1.16
- Update the hash value
- Remove upstreamed patches:
  0001-configure.ac-remove-manual-compiler-check-with-AC_TR.patch
  0003-Makefile.in-add-LDFLAGS-to-linking-stage.patch
- Tweak patches for the new version:
  0004-Makefile.in-replace-IROOT-by-DESTDIR.patch
  0005-Makefile.in-make-install-fix.patch

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