drm/i915/psr: Carry su area in crtc_state

Su_area is needed when configuring CUR_POS_ERLY_TPT and
PIPE_SRC_SZ_ERLY_TPT. Store it into intel_crtc_state->psr2_su_area.

Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Mika Kahola <mika.kahola@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231218175004.52875-4-jouni.hogander@intel.com