Add routines to update nam_ps

Add SQL queries to change nam_ps value and function which uses them.

Change-Id: I24fb79e084b2dfa6a81b52f448b94a86e47014ef
diff --git a/src/db.c b/src/db.c
index d20b8b6..aa4726c 100644
--- a/src/db.c
+++ b/src/db.c
@@ -33,6 +33,8 @@
 	[AUC_UPD_SQN] = "UPDATE auc_3g SET sqn = ? WHERE subscriber_id = ?",
 	[UPD_PURGE_CS_BY_IMSI] = "UPDATE subscriber SET ms_purged_cs=1 WHERE imsi = ?",
 	[UPD_PURGE_PS_BY_IMSI] = "UPDATE subscriber SET ms_purged_ps=1 WHERE imsi = ?",
+	[SET_NAM_PS_BY_IMSI] = "UPDATE subscriber SET nam_ps=1 WHERE imsi = ?",
+	[UNSET_NAM_PS_BY_IMSI] = "UPDATE subscriber SET nam_ps=0 WHERE imsi = ?",
 };
 
 static void sql3_error_log_cb(void *arg, int err_code, const char *msg)