rockchip: video: add mpixelclock settings from Linux driver

The Linux driver now supports higher mpixelclock settings.
Add these to rockchip_phy_config[] and rockchip_mpll_cfg[].

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Simon Glass <sjg@chromium.org>