drm/amd/display: Do cursor updates after stream updates

[Why]
Cursor updates used to happen after vblank/flip/stream updates before
the stream update refactor. They now happen before stream updates
which means that they're not going to be synced with fb changes
and that they're going to programmed for pipes that we're disabling
within the same commit.

[How]
Move them after stream updates.

Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: David Francis <David.Francis@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>