drm/qxl: Use the hotspot properties from cursor planes

drm/qxl: Use the hotspot properties from cursor planes

Atomic modesetting got support for mouse hotspots via the hotspot
properties. Port the legacy kms hotspot handling to the new properties
on cursor planes.

Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: virtualization@lists.linux-foundation.org
Cc: spice-devel@lists.freedesktop.org
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231023074613.41327-5-aesteve@redhat.com