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
diff --git a/doc/examples/Makefile.am b/doc/examples/Makefile.am
index 0b06130..ac87457 100644
--- a/doc/examples/Makefile.am
+++ b/doc/examples/Makefile.am
@@ -1,3 +1,15 @@
+# all config examples must be listed here unconditionally, so that
+# all of them end up in the release tarball (see OS#6349)
+EXTRA_DIST = \
+	osmo-trx-uhd/osmo-trx-limesdr.cfg \
+	osmo-trx-uhd/osmo-trx-usrp_b200.cfg \
+	osmo-trx-uhd/osmo-trx-uhd.cfg \
+	osmo-trx-uhd/osmo-trx-umtrx.cfg \
+	osmo-trx-lms/osmo-trx-limesdr.cfg \
+	osmo-trx-lms/osmo-trx-lms.cfg \
+	osmo-trx-ipc/osmo-trx-ipc.cfg \
+	$(NULL)
+
 OSMOCONF_FILES =
 osmoconfdir = $(sysconfdir)/osmocom
 
@@ -19,7 +31,6 @@
 endif
 
 osmoconf_DATA = $(OSMOCONF_FILES)
-EXTRA_DIST = $(OSMOCONF_FILES)
 
 CFG_FILES = find $(srcdir) -type f -name '*.cfg*' | sed -e 's,^$(srcdir),,'