[WIP] drm/rockchip: vop2: Improve display modes handling on rk3588

The initial vop2 support for rk3588 in mainline is not able to handle
all display modes supported by connected displays, e.g.
2560x1440-75.00Hz, 2048x1152-60.00Hz, 1024x768-60.00Hz.

Additionally, it doesn't cope with non-integer refresh rates like 59.94,
29.97, 23.98, etc.

Improve HDMI0 clocking in order to support the additional display modes.

Fixes: 5a028e8f ("drm/rockchip: vop2: Add support for rk3588")
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>