MLBEDSW-6613: Implement tile padding

Implement new padding mode which pads two edges of the IFM with the
current values of those edges

Signed-off-by: Rickard Bolin <rickard.bolin@arm.com>
Change-Id: I8523e0cabdac80b48710703859003e33050cc150
diff --git a/ethosu/vela/tflite_graph_optimiser.py b/ethosu/vela/tflite_graph_optimiser.py
index 0f199de..611046b 100644
--- a/ethosu/vela/tflite_graph_optimiser.py
+++ b/ethosu/vela/tflite_graph_optimiser.py
@@ -238,6 +238,9 @@
         top, left, bottom, right = explicit_padding
         top_pad, bottom_pad = calc_explicit_padding(int(input_shape.height), int(s_y), int(k_h), int(top), int(bottom))
         left_pad, right_pad = calc_explicit_padding(int(input_shape.width), int(s_x), int(k_w), int(left), int(right))
+    elif padding_type == Padding.TILE:
+        # The values in the explicit padding only represent the "direction" in which to pad
+        top_pad, left_pad, bottom_pad, right_pad = explicit_padding
     else:
         raise UnsupportedFeatureError(f"Unsupported padding = {padding_type} for padding calculation")
     padding = (top_pad, left_pad, bottom_pad, right_pad)