Changes

doc/examples: fix missing config files in release tarballs

All config file examples must be listed in EXTRA_DIST unconditionally.
Adding them conditionally results in incomplete release tarballs,
containing only some '*.cfg' files and failing to build.

Change-Id: Iffb6d7577de175fc5d14642f0af6852508d74e69
Related: OS#6349
(cherry picked from commit a2d76f1d2fe7a1b162fe183695fb479b13c27aac)