include: reorganize headers file to include/osmocom/[gsm|core]

This patch moves all GSM-specific definitions to include/osmocom/gsm.
Moreover, the headers in include/osmocore/ have been moved to
include/osmocom/core.

This has been proposed by Harald Welte and Sylvain Munaunt.

Tested with `make distcheck'.

Signed-off-by: Pablo Neira Ayuso <pablo@gnumonks.org>
diff --git a/include/osmocom/gsm/protocol/Makefile.am b/include/osmocom/gsm/protocol/Makefile.am
new file mode 100644
index 0000000..8483f10
--- /dev/null
+++ b/include/osmocom/gsm/protocol/Makefile.am
@@ -0,0 +1,6 @@
+osmogsm_proto_HEADERS = gsm_03_41.h \
+			gsm_04_08.h gsm_04_11.h gsm_04_12.h gsm_04_80.h \
+			gsm_08_08.h gsm_08_58.h \
+			gsm_12_21.h
+
+osmogsm_protodir = $(includedir)/osmocom/gsm/protocol