drm/amdgpu/dce8: Use cursor_set2 hook for enabling / disabling the HW cursor

drm/amdgpu/dce8: Use cursor_set2 hook for enabling / disabling the HW cursor

The cursor_set2 hook provides the cursor hotspot position within the
cursor image. When the hotspot position changes, we can adjust the cursor
position such that the hotspot doesn't move on the screen. This prevents
the cursor from appearing to intermittently jump around on the screen
when the position of the hotspot within the cursor image changes.

Port of radeon commits:
2b77530a694633583f8d7330cd25b2fc68b1b03d
bcd6dc80d0b4ed4180c4e688e15f67b965fdb2fc

Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>