Refreshing ECM MAC
Refreshing ECM MAC

Reason for change: As ECM Mac is obtained using snmp query, moved it to loop,
                   to ensure that snmp query value is proper
Test Procedure: Verify ECM MAC in /tmp/.deviceDetails.cache
Risks: Low
Signed-off-by: gtheres <Geethu_TheresK2@comcast.com>

Change-Id: I21f04015acf4d09691797ea44bb64c3f6356c36f

rdkcmf/rdk-sysint