Added a Network Interface Card enable boolean control

Added a boolean NIC enable control to allow the NIC to be enabled or
disabled. The control is added to support the Redfish InterfaceEnabled
property.

Tested:

Confirmed that the DBus property changed state after using the "ip
link set eth(x) down" and "up" command.
Also confirmed the value, when written using Redfish, changed the NIC
state.

Change-Id: Ie88e20430138f6f6cc3142440a9f2b2437ab1885
Signed-off-by: Johnathan Mantey <johnathanx.mantey@intel.com>
diff --git a/xyz/openbmc_project/Network/EthernetInterface.interface.yaml b/xyz/openbmc_project/Network/EthernetInterface.interface.yaml
index ee54145..48300d7 100644
--- a/xyz/openbmc_project/Network/EthernetInterface.interface.yaml
+++ b/xyz/openbmc_project/Network/EthernetInterface.interface.yaml
@@ -58,6 +58,10 @@
       type: boolean
       description: >
           Boolean for accepting router advertisements in IPv6
+    - name: NICEnabled
+      type: boolean
+      description: >
+          Boolean for to enabling or disabling the ethernet port
 
 enumerations:
     - name: LinkLocalConf