IPv6: Remove AddressState from redfish response.

Network backend does not return the AddressState and its currently displayed as null. This is misleading the user.

This commit removes this property until backend supports.

Tested by:
 Verify ethernet interface does not return AddressState for IPv6

Change-Id: I5489f57ce3d50d1480033f27adf1bc95153fdd18
Signed-off-by: Sunitha Harish <sunithaharish04@gmail.com>
diff --git a/redfish-core/lib/ethernet.hpp b/redfish-core/lib/ethernet.hpp
index ec754fa..9563290 100644
--- a/redfish-core/lib/ethernet.hpp
+++ b/redfish-core/lib/ethernet.hpp
@@ -1691,7 +1691,7 @@
         ipv6["Address"] = ipv6Config.address;
         ipv6["PrefixLength"] = ipv6Config.prefixLength;
         ipv6["AddressOrigin"] = ipv6Config.origin;
-        ipv6["AddressState"] = nullptr;
+
         ipv6Array.push_back(std::move(ipv6));
         if (ipv6Config.origin == "Static")
         {