drm/panel: simple: push blanking limit on RK32FN48H

Push horizontal front porch and vertical back porch blanking limit.
This allows to get a 60 fps sharp.

Signed-off-by: Raphael Gallais-Pou <raphael.gallais-pou@foss.st.com>
Reviewed-by: Jessica Zhang <quic_jesszhan@quicinc.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20240205-ltdc_mp13-v1-5-116d43ebba75@foss.st.com


Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240205-ltdc_mp13-v1-5-116d43ebba75@foss.st.com