drm/amd/display: Add retry to read ddc_clock pin

[WHY]
On customer board, there is one pluse (1v , < 1ms) on
DDC_CLK pin when plug / unplug DP cable. Driver will read
it and config DP to HDMI/DVI dongle.

[HOW]
If there is a real dongle, DDC_CLK should be always pull high.
Try to read again to recovery this special case. Retry times = 3.
Need additional 3ms to detect DP passive dongle(3 failures)

Signed-off-by: Paul Hsieh <paul.hsieh@amd.com>
Reviewed-by: Eric Yang <eric.yang2@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>