[why]
In the TEST_MSIC dpcd register field definition, the test equipment
has the option to choose between YCbCr601 or YCbCr709.
We will apply corresponding YCbCr coefficient based on this test
request.

[how]
Add a new input parameter in dc_link_dp_set_test_pattern to allow the
selection between different color space.
Signed-off-by: Wenjing Liu <Wenjing.Liu@amd.com>
Reviewed-by: Nikola Cornij <Nikola.Cornij@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>