sms: Encapsulate SMS queue related config parameters

Introduce a 'struct sms_queue_config' that holds all config parameters
related to the SMS queue.

Change-Id: I559ab7a6e0502a1a12a662ebd5591875d47ec7b2
diff --git a/include/osmocom/msc/sms_queue.h b/include/osmocom/msc/sms_queue.h
index ef73baf..492ae72 100644
--- a/include/osmocom/msc/sms_queue.h
+++ b/include/osmocom/msc/sms_queue.h
@@ -5,10 +5,18 @@
 struct gsm_sms_queue;
 struct vty;
 
+struct sms_queue_config {
+	char *db_file_path;			/* SMS database file path */
+	int max_fail;				/* maximum number of delivery failures */
+	int max_pending;			/* maximum number of gsm_sms_pending in RAM */
+};
+
+struct sms_queue_config *sms_queue_cfg_alloc(void *ctx);
+
 #define VSUB_USE_SMS_PENDING "SMS-pending"
 #define MSC_A_USE_SMS_PENDING "SMS-pending"
 
-int sms_queue_start(struct gsm_network *, int in_flight);
+int sms_queue_start(struct gsm_network *net);
 int sms_queue_trigger(struct gsm_sms_queue *);
 
 /* vty helper functions */