drm/amd/display: DP link layer test 4.2.1.1 fix due to specs update

[why]
DP link layer CTS specs updated to change the test parameters in test
4.2.1.1.
Before it requires source to delay 400us on aux no reply.
With the specs updates Errata5, it requires source to delay 3.2ms
(based on LTTPR aux timeout)
This causes our test to fail after updating with the latest test
equipment firmware.

[how]
the change is to allow LTTPR 3.2ms aux timeout delay by default.
And set back to 400us if LTTPR feature is not enabled.
We will set 3.2ms and always enable LTTPR non transparent mode
if LTTPR feature is enabled and LTTPR is present.

Signed-off-by: Wenjing Liu <wenjing.liu@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Krunoslav Kovac <Krunoslav.Kovac@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>