MLBEDSW-3583: Prevent DMA for converted FullyConnected

Do not use DMA for weights of a FullyConnected op that has
been converted to a Conv2D.

Change-Id: Ibf6710c0a1723c8b48c563ca204f274af5ca88ce
Signed-off-by: Louis Verhaard <louis.verhaard@arm.com>
diff --git a/ethosu/vela/graph_optimiser.py b/ethosu/vela/graph_optimiser.py
index 5889905..85c2b60 100644
--- a/ethosu/vela/graph_optimiser.py
+++ b/ethosu/vela/graph_optimiser.py
@@ -338,6 +338,7 @@
                 "stride_h": 1,
                 "stride_w": 1,
                 "strides": (1, 1, 1, 1),
+                "is_converted_fc": True,
             }
 
             prev_op = ifm.ops[0]