VOL-849: Initial changes to compile with BAL 2.6

The OPENOLT_BAL_2.6.0.1.patch file is required to compile this commit.
This patch file has been uploaded to the Broadcom common CS3233745.

Change-Id: I8dbaca0f56cdf6058603371e9c30d2ce6b04df40
diff --git a/src/stats_collection.cc b/src/stats_collection.cc
index de11c72..5ec33bc 100644
--- a/src/stats_collection.cc
+++ b/src/stats_collection.cc
@@ -60,6 +60,7 @@
     return port_stats;
 }
 
+#if 0
 openolt::FlowStatistics* get_default_flow_statistics() {
     openolt::FlowStatistics* flow_stats = new openolt::FlowStatistics;
     flow_stats->set_flow_id(-1);
@@ -70,6 +71,7 @@
 
     return flow_stats;
 }
+#endif
 
 openolt::PortStatistics* collectPortStatistics(int intf_id, bcmbal_intf_type intf_type) {
 
@@ -119,6 +121,7 @@
 
 }
 
+#if 0
 openolt::FlowStatistics* collectFlowStatistics(bcmbal_flow_id flow_id, bcmbal_flow_type flow_type) {
 
     bcmos_errno err;
@@ -156,6 +159,7 @@
 
     return flow_stats;
 }
+#endif
 
 
 void* stats_collection(void* x) {