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/logging.c b/src/logging.c
index 89ca6ce..653c80d 100644
--- a/src/logging.c
+++ b/src/logging.c
@@ -34,9 +34,9 @@
 #include <time.h>
 #include <errno.h>
 
-#include <osmocore/talloc.h>
-#include <osmocore/utils.h>
-#include <osmocore/logging.h>
+#include <osmocom/core/talloc.h>
+#include <osmocom/core/utils.h>
+#include <osmocom/core/logging.h>
 
 #include <osmocom/vty/logging.h>	/* for LOGGING_STR. */