drm/amd/display: Fix cursor pos at overlay plane edges on DCN4

drm/amd/display: Fix cursor pos at overlay plane edges on DCN4

[Why&How]
On DCN4, when cursor straddles the left/top edge of an overlay plane, the
recout-relative position becomes negative. These negative values wrap
to large positive numbers when cast to uint32_t, causing the cursor on the
the overlay plane to disappear.

Fix by adding hotspot adjustment and position clamping after the
recout-relative calculation, matching the existing ODM/MPC slice
boundary handling.

Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Ivan Lipski <ivan.lipski@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>