drm/amd/display: Explicitly specify update type per plane info change

[Why]
The bit for flip addr is being set causing the determination for
FAST vs MEDIUM to always return MEDIUM when plane info is provided
as a surface update. This causes extreme stuttering for the typical
atomic update path on Linux.

[How]
Don't use update_flags->raw for determining FAST vs MEDIUM. It's too
fragile to changes like this.

Explicitly specify the update type per update flag instead. It's not
as clever as checking the bits itself but at least it's correct.

Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Acked-by: Eryk Brol <Eryk.Brol@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>