Memory access exception in nn_conv2d_hstrip_tail_deep_padded

[keithm-xmos]

The following integration test configs cause a memory access exception in nn_conv2d_hstrip_tail_deep_padded.

NOTE: These tests pass when running on the x86 host.

integration_test/test_single_op_models/test_conv2d/test_conv2d.py::test_output[CONFIGS[4]]
integration_test/test_single_op_models/test_conv2d/test_conv2d.py::test_converted_single_op_model[CONFIGS[4]]
  4:
    K_h: 9
    K_w: 9
    height: 15
    input_channels: 32
    num_threads: 1
    output_channels: 4
    padding: same
    strides:
    - 2
    - 2
    width: 20

integration_test/test_single_op_models/test_conv2d/test_fused_relu/test_custom_relu_conv2d.py::test_output[CONFIGS[0]]
integration_test/test_single_op_models/test_conv2d/test_fused_relu/test_custom_relu_conv2d.py::test_idempotence[CONFIGS[0]]
  0:
    K_h: 2
    K_w: 3
    height: 5
    input_channels: 32
    max_value: 1.0
    num_threads: 1
    output_channels: 4
    padding: same
    strides:
    - 1
    - 2
    width: 20

[astewart-xmos]

This issue may have been resolved by the fix for #4 in commit a5f0c8b.

Once that fix is tested for #4, this one should be checked as well.