VOL-1381 and VOL-1091 Add feature to collect PMmetrics of OLT, this will collect Tx and Rx and posts to kafka. This commit is also related to changes of commit 72b25abd4e804596413558ef10f098c2262dd65d voltha-go
Updated review comments

Updated with code optimization
Updated with dep files
Updated fix for sanity test
Updated with gomod changes

Change-Id: I899e855812a6eda812c64664a9154321cdb16876
diff --git a/adaptercore/olt_platform.go b/adaptercore/olt_platform.go
index 5f48bc6..ed6d489 100644
--- a/adaptercore/olt_platform.go
+++ b/adaptercore/olt_platform.go
@@ -127,6 +127,17 @@
 	return 0
 }
 
+//PortNoToIntfID returns portnumber derived from interfaceID
+func PortNoToIntfID(portno uint32, intfType voltha.Port_PortType) uint32 {
+	if (intfType) == voltha.Port_ETHERNET_NNI {
+		return (1 << 16) ^ portno
+	}
+	if (intfType) == voltha.Port_PON_OLT {
+		return (2 << 28) ^ portno
+	}
+	return 0
+}
+
 //IntfIDFromNniPortNum returns Intf ID derived from portNum
 func IntfIDFromNniPortNum(portNum uint32) uint32 {
 	return portNum & 0xFFFF