Split include/Makefile.am content into subdirs

When someone is modifying a given library there's no need to be looking
at a common file contains tons of lines from different libraries.
Furthermore, this removes the need of "nobase" autofoo prefix, hence
following the usual directive of having one Makefile per directory.

Change-Id: I785891c2f89114bf8303c799094b637d3d25ac71
diff --git a/include/osmocom/gsm/Makefile.am b/include/osmocom/gsm/Makefile.am
new file mode 100644
index 0000000..2c59e55
--- /dev/null
+++ b/include/osmocom/gsm/Makefile.am
@@ -0,0 +1,67 @@
+SUBDIRS = protocol
+
+BUILT_SOURCES = gsm0503.h
+
+osmogsm_HEADERS = \
+	a5.h \
+	abis_nm.h \
+	apn.h \
+	bts_features.h \
+	cbsp.h \
+	comp128.h \
+	comp128v23.h \
+	bitvec_gsm.h \
+	gan.h \
+	gsm0341.h \
+	gsm0411_smc.h \
+	gsm0411_smr.h \
+	gsm0411_utils.h \
+	gsm0480.h \
+	gsm0502.h \
+	gsm0503.h \
+	bsslap.h \
+	bssmap_le.h \
+	gad.h \
+	gsm0808.h \
+	gsm0808_lcs.h \
+	gsm29205.h \
+	gsm0808_utils.h \
+	gsm23003.h \
+	gsm23236.h \
+	gsm29118.h \
+	gsm48.h \
+	gsm48_arfcn_range_encode.h \
+	gsm48_ie.h \
+	gsm48_rest_octets.h \
+	gsm_utils.h \
+	gsup.h \
+	gsup_sms.h \
+	i460_mux.h \
+	ipa.h \
+	iuup.h \
+	lapd_core.h \
+	lapdm.h \
+	meas_rep.h \
+	mncc.h \
+	prim.h \
+	l1sap.h \
+	oap.h \
+	oap_client.h \
+	rsl.h \
+	rxlev_stat.h \
+	sysinfo.h \
+	tlv.h \
+	$(NULL)
+
+osmogsmdir = $(includedir)/osmocom/gsm
+
+noinst_HEADERS = \
+	kasumi.h \
+	gea.h \
+	$(NULL)
+
+gsm0503.h: $(top_srcdir)/utils/conv_gen.py $(top_srcdir)/utils/conv_codes_gsm.py
+	$(AM_V_GEN)python3 $(top_srcdir)/utils/conv_gen.py gen_header gsm \
+		--target-path $(builddir)/
+
+CLEANFILES = gsm0503.h