[Why]

The OTG_VUPDATE_KEEPOUT register and fields is
available on DCN10, and named the same in DCN20.

[How]

Move register definition and programming function
to dcn10 optc.

There is no functional change.
Signed-off-by: Leo Li <sunpeng.li@amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>