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/src/gsmtap_util.c b/src/gsmtap_util.c
index abee4da..6d02d58 100644
--- a/src/gsmtap_util.c
+++ b/src/gsmtap_util.c
@@ -24,13 +24,13 @@
 
 #ifdef HAVE_SYS_SELECT_H
 
-#include <osmocore/gsmtap_util.h>
-#include <osmocore/logging.h>
-#include <osmocore/protocol/gsm_04_08.h>
-#include <osmocore/gsmtap.h>
-#include <osmocore/msgb.h>
-#include <osmocore/rsl.h>
-#include <osmocore/select.h>
+#include <osmocom/core/gsmtap_util.h>
+#include <osmocom/core/logging.h>
+#include <osmocom/core/gsmtap.h>
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/select.h>
+#include <osmocom/gsm/protocol/gsm_04_08.h>
+#include <osmocom/gsm/rsl.h>
 
 #include <arpa/inet.h>
 #include <sys/socket.h>