tests/acceptance/integratorcp: Verify Tux is displayed on framebuffer

tests/acceptance/integratorcp: Verify Tux is displayed on framebuffer

Add a test that verifies the Tux logo is displayed on the framebuffer.

We simply follow the OpenCV "Template Matching with Multiple Objects"
tutorial, replacing Lionel Messi by Tux:
https://docs.opencv.org/4.2.0/d4/dc6/tutorial_py_template_matching.html

When OpenCV and NumPy are installed, this test can be run using:

  $ AVOCADO_ALLOW_UNTRUSTED_CODE=hmmm \
    avocado --show=app,framebuffer run -t device:framebuffer \
      tests/acceptance/machine_arm_integratorcp.py
  JOB ID     : 8c46b0f8269242e87d738247883ea2a470df949e
  JOB LOG    : avocado/job-results/job-2020-01-31T21.38-8c46b0f/job.log
   (1/1) tests/acceptance/machine_arm_integratorcp.py:IntegratorMachine.test_framebuffer_tux_logo:
  framebuffer: found Tux at position [x, y] = (0, 0)
  PASS (3.96 s)
  RESULTS    : PASS 1 | ERROR 0 | FAIL 0 | SKIP 0 | WARN 0 | INTERRUPT 0 | CANCEL 0
  JOB TIME   : 4.23 s

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Message-id: 20200225172501.29609-5-philmd@redhat.com
Message-Id: <20200131211102.29612-3-f4bug@amsat.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>