MEAN implementation changed to Average Pool

This is a small commit which changes one of
the four MEAN implementations to a simpler
one, using an AvgPool instead of a
DepthwiseConv.

Signed-off-by: Dwight Lidman <dwight.lidman@arm.com>
Change-Id: I9e8af071e8b820796577ee4792b4812a1212602b
diff --git a/ethosu/vela/test/test_supported_operators.py b/ethosu/vela/test/test_supported_operators.py
index aad2849..355b472 100644
--- a/ethosu/vela/test/test_supported_operators.py
+++ b/ethosu/vela/test/test_supported_operators.py
@@ -864,7 +864,7 @@
 
 
 def test_mean_hw_product():
-    op = create_mean([1, 64, 64, 16], [1, 1, 16], [1, 2], DataType.uint8, {})
+    op = create_mean([1, 64, 64, 16], [1, 16], [1, 2], DataType.uint8, {})
     assert support.is_operator_supported(op)
     op = create_mean([1, 65, 64, 16], [1, 1, 1, 16], [1, 2], DataType.int8, {"keep_dims": True})
     assert not support.is_operator_supported(op)
@@ -875,3 +875,10 @@
     assert support.is_operator_supported(op)
     op = create_mean([1, 16, 17, 16], [1, 1, 1, 16], [1, 2], DataType.int8, {"keep_dims": True})
     assert not support.is_operator_supported(op)
+
+
+def test_mean_hw_product_avgpool():
+    op = create_mean([1, 200, 200, 16], [1, 16], [1, 2], DataType.uint8, {"keep_dims": False})
+    assert support.is_operator_supported(op)
+    op = create_mean([1, 200, 200, 16], [1, 1, 1, 16], [1, 2], DataType.int8, {"keep_dims": True})
+    assert not support.is_operator_supported(op)