[microNPU] Add relu6 relu_n1_to_1 test cases for Ethos-U (#13645)

Tests are extended with cases with activations relu6 and relu_n1_to_1. Test cases contain conv2d operation + activation because separate activation is not offloaded to NPU.

tests/python/contrib/test_ethosu/test_codegen.py

@@ -1132,6 +1132,65 @@ def leaky_relu_func(x):
     )
 
 
+# conv2d + relu_n1_to_1 is used because separate activation is not offloaded to NPU.
+def test_tflite_relu_n1_to_1():
+    np.random.seed(0)
+    accel_type = "ethos-u55-256"
+    ifm_shape = (1, 55, 34, 3)
+    kernel_shape = (3, 2)
+    strides = (1, 1)
+
+    @tf.function
+    def conv2d_relu_n1_to_1(x):
+        tf_strides = [1, strides[0], strides[1], 1]
+        weight_shape = [kernel_shape[0], kernel_shape[1], ifm_shape[3], 3]
+        weight = tf.constant(np.random.uniform(size=weight_shape), dtype=tf.float32)
+        op = tf.nn.conv2d(
+            x,
+            weight,
+            strides=tf_strides,
+            padding="VALID",
+        )
+        # The specific pattern will be replaced into RELU_N1_TO_1 by tflite.
+        return tf.math.maximum(-1.0, tf.math.minimum(op, 1.0))
+
+    infra.compare_tvm_with_tflite(
+        conv2d_relu_n1_to_1,
+        [ifm_shape],
+        accel_type,
+        enable_cascader=True,
+    )
+
+
+# conv2d + relu6 is used because separate activation is not offloaded to NPU.
+def test_tflite_relu6():
+    np.random.seed(0)
+    accel_type = "ethos-u55-256"
+    ifm_shape = (1, 55, 34, 3)
+    kernel_shape = (3, 2)
+    strides = (1, 1)
+
+    @tf.function
+    def conv2d_relu6(x):
+        tf_strides = [1, strides[0], strides[1], 1]
+        weight_shape = [kernel_shape[0], kernel_shape[1], ifm_shape[3], 3]
+        weight = tf.constant(np.random.uniform(size=weight_shape), dtype=tf.float32)
+        op = tf.nn.conv2d(
+            x,
+            weight,
+            strides=tf_strides,
+            padding="VALID",
+        )
+        return tf.nn.relu6(op)
+
+    infra.compare_tvm_with_tflite(
+        conv2d_relu6,
+        [ifm_shape],
+        accel_type,
+        enable_cascader=True,
+    )
+
+
 @pytest.mark.parametrize("accel_type", ACCEL_TYPES)
 @pytest.mark.parametrize("ifm_shape", [(1, 14), (1, 151)])
 @pytest.mark.parametrize("ofm_channels", [32, 64])