codec: Add the missing bits for include to install and pkgconfig to work

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
diff --git a/configure.in b/configure.in
index 30f9d9c..825152d 100644
--- a/configure.in
+++ b/configure.in
@@ -99,9 +99,11 @@
 
 AC_OUTPUT(
 	libosmocore.pc
+	libosmocodec.pc
 	libosmovty.pc
 	include/osmocom/Makefile
 	include/osmocom/vty/Makefile
+	include/osmocom/codec/Makefile
 	include/osmocom/crypt/Makefile
 	include/osmocore/Makefile
 	include/osmocore/protocol/Makefile