drm/rockchip: dw_hdmi: Enable 4K@60Hz mode on RK3399 and RK356x

Use a maximum TMDS clock rate limit of 594MHz to enable use of HDMI2.0
modes, e.g. 4K@60Hz, on RK3399 and RK3568.

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Tested-by: Diederik de Haas <didi.debian@cknow.org> # Quartz64 Model B
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20240908145511.3331451-7-jonas@kwiboo.se