codec: Add functions for AMR s->d bits and d->s bits

These functions implement re-ordering of bits as per TS 06.90 / 26.101
based on the already existing tables we've had in libosmocoding.

Change-Id: Ia4ac2aea2e96f9185f082a07ca64dfc5276efb46
diff --git a/src/codec/Makefile.am b/src/codec/Makefile.am
index ac33aa0..778eb2a 100644
--- a/src/codec/Makefile.am
+++ b/src/codec/Makefile.am
@@ -3,7 +3,7 @@
 # before making any modifications: https://www.gnu.org/software/libtool/manual/html_node/Versioning.html
 LIBVERSION=2:0:2
 
-AM_CPPFLAGS = -I$(top_srcdir)/include $(TALLOC_CFLAGS)
+AM_CPPFLAGS = -I$(top_srcdir)/include -I$(top_builddir)/include $(TALLOC_CFLAGS)
 AM_CFLAGS = -Wall
 
 if ENABLE_PSEUDOTALLOC