drm/i915/display: Workaround cursor left overs with PSR2 selective fetch enabled

Not sure why but when moving the cursor fast it causes some artifacts
of the cursor to be left in the cursor path, adding some pixels above
the cursor to the damaged area fixes the issue, so leaving this as a
workaround until proper fix is found.

This is reproducile on TGL and ADL-P.

Cc: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Reviewed-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210914212507.177511-3-jose.souza@intel.com