Add "-Wall" to the compile rules of the non-asn1c-generated source code

This is actually default in all other osmocom projects, and it's a
big surprise that it hadn't been enabled for osmo-iuh.  Now we finally
can see that there are e.g. unused static functions in the code.

Change-Id: I8d52b11e3f476ffd77f3ab185b679817cd3b2163

src/Makefile.am

@@ -42,7 +42,7 @@ gen_ranap.stamp: $(ASN1_ROOT)/ranap/RANAP-PDU-Contents.asn $(ASN1TOSTRUCT)
 
 ranap_decoder.c ranap_encoder.c: gen_ranap.stamp
 
-AM_CFLAGS = -I$(top_srcdir)/include -I$(top_builddir)/include \
+AM_CFLAGS = -Wall -I$(top_srcdir)/include -I$(top_builddir)/include \
 	    $(OSMOCORE_CFLAGS) $(OSMOVTY_CFLAGS) $(OSMOGSM_CFLAGS) \
 	    $(OSMONETIF_CFLAGS) $(ASN1C_CFLAGS) $(OSMOSIGTRAN_CFLAGS)
 

src/tests/Makefile.am

@@ -1,4 +1,4 @@
-AM_CFLAGS = -g -I$(top_srcdir)/src/tests \
+AM_CFLAGS = -g -Wall -I$(top_srcdir)/src/tests \
 	-I$(top_srcdir)/include -I$(top_builddir)/include \
 	$(OSMOVTY_CFLAGS) $(OSMOCORE_CFLAGS) $(OSMOGSM_CFLAGS) \
 	$(OSMONETIF_CFLAGS) $(ASN1C_CFLAGS) $(OSMOSIGTRAN_CFLAGS)