MLBEDSW-6881 SHAPE single op network is optimised to nothing

Fixed by adding an operation to copy the statically optimised
data to the subgraph output.

Change-Id: Ica757e37d5460237973444ffd39c7d2850f319e3
Signed-off-by: Fredrik Svedberg <fredrik.svedberg@arm.com>
diff --git a/ethosu/vela/operation.py b/ethosu/vela/operation.py
index b4d0e48..05c236a 100644
--- a/ethosu/vela/operation.py
+++ b/ethosu/vela/operation.py
@@ -596,6 +596,10 @@
     def original_type(self):
         return self._original_type
 
+    @property
+    def type_changed(self):
+        return self.type != self.original_type
+
     def get_kernel_size(self):
         weights = self.weights
         if weights and self.type.npu_block_type in (NpuBlockType.ConvolutionDepthWise, NpuBlockType.ConvolutionMxN):