drm/i915/psr: Extend SU area to cover cursor fully if needed

In case early transport is enabled SU area needs to be extended
to cover cursor area fully when cursor is in SU area.

Bspec: 68927

Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Mika Kahola <mika.kahola@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231218175004.52875-3-jouni.hogander@intel.com