Add InternalFailure error for MAC Address

Using the InternalFailure error here:
https://github.com/openbmc/phosphor-networkd/blob/057ff0daf0fd4d2617c5e50e2f9a095e06e3c24b/ethernet_interface.cpp#L710

sdbusplus now supports errors on properties.

Change-Id: I8dc9d8df5203ceca1ef33edf9a9a96eb1fa0691e
Signed-off-by: Gunnar Mills <gmills@us.ibm.com>
diff --git a/xyz/openbmc_project/Network/MACAddress.interface.yaml b/xyz/openbmc_project/Network/MACAddress.interface.yaml
index 96f4177..df092f2 100644
--- a/xyz/openbmc_project/Network/MACAddress.interface.yaml
+++ b/xyz/openbmc_project/Network/MACAddress.interface.yaml
@@ -8,3 +8,4 @@
           MAC address of the ethernet interface.
       errors:
         - xyz.openbmc_project.Common.Error.InvalidArgument
+        - xyz.openbmc_project.Common.Error.InternalFailure