drm/amd/display: Use TPS4 instead of CP2520_3 for phy pattern 7

[Description]
We originally use TPS4 phy test pattern for test pattern 7.
On RV we switched to a new method to use CP2520.
CP2520 should produce the same result.
However in reality, it fails DP PHY automation test.
We use the original method instead.

Signed-off-by: Wenjing Liu <Wenjing.Liu@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>