drm/amd/display: Increase timeout for DP Disable

[WHY]
When disabling DP video, the current REG_WAIT timeout
of 50ms is too low for certain cases with very high
VSYNC intervals.

[HOW]
Increase the timeout to 102ms, so that
refresh rates as low as 10Hz can be handled properly.

Signed-off-by: Wesley Chalmers <Wesley.Chalmers@amd.com>
Reviewed-by: Aric Cyr <Aric.Cyr@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: <stable@vger.kernel.org>