drm/amd/display: always use 100us for cr aux rd interval

[why]
The cr training aux rd interval is
modified without following specs requirements.
According to the commit message the change was not intended to modify the value.
Therefore it looks like it is caused by a typo in the change.

Signed-off-by: Wenjing Liu <wenjing.liu@amd.com>
Acked-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>