sgx: update NFD labels

NFD master and the upcoming release v0.10.0 dropped the
"custom-" prefix from custom labels. Update the default
SgxDevicePlugin sample accordingly.

Signed-off-by: Mikko Ylinen <mikko.ylinen@intel.com>

Author: mythi

deployments/operator/samples/deviceplugin_v1_sgxdeviceplugin.yaml

@@ -9,4 +9,4 @@ spec:
   provisionLimit: 110
   logLevel: 4
   nodeSelector:
-    feature.node.kubernetes.io/custom-intel.sgx: 'true'
+    feature.node.kubernetes.io/intel.sgx: 'true'