Install cfg files with autotools

Cfg files are moved to doc/examples like in other osmocom projects.
All the cfg files get installed into
$prefix/share/doc/osmo-pcap/examples/$subdir/, and 1 script per binary is
installed into /etc/osmocom.

Change-Id: If3f3a7d3867c0d4d2b1fe01f465532d1ce4bda66
diff --git a/Makefile.am b/Makefile.am
index 0f4a249..1dd1ff4 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,6 +1,6 @@
 AUTOMAKE_OPTIONS = foreign dist-bzip2 1.6
 
-SUBDIRS = include src contrib tests
+SUBDIRS = include src contrib doc tests
 
 BUILT_SOURCES = $(top_srcdir)/.version
 EXTRA_DIST = git-version-gen .version