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:
aec28b4efcb10805d6e2e3ada120ee2bb64cf0df
c39cbd267757e3d9b6e4ae02a3f468c58e7bced1

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