Move vlr.h & vlr_sgs.h into osmocom/vlr/

Prepare libvlr to be independent, start by moving the vlr headers
into its own directory.

Change-Id: I8b18b05091b35e744b3234d1ce0d537f56bccf07
diff --git a/tests/sms_queue/sms_queue_test.c b/tests/sms_queue/sms_queue_test.c
index cc78e14..bca60b1 100644
--- a/tests/sms_queue/sms_queue_test.c
+++ b/tests/sms_queue/sms_queue_test.c
@@ -24,7 +24,7 @@
 #include <osmocom/core/application.h>
 
 #include <osmocom/msc/debug.h>
-#include <osmocom/msc/vlr.h>
+#include <osmocom/vlr/vlr.h>
 #include <osmocom/msc/gsm_data.h>
 #include <osmocom/msc/gsm_04_11.h>
 #include <osmocom/msc/db.h>