Add driver for the HDMI/eDP TX Combo PHY found on Rockchip RK3588 SoC.

The PHY is based on a Samsung IP block and supports HDMI 2.1 TMDS, FRL
and eDP links.  The maximum data rate is 12Gbps (FRL), while the minimum
is 250Mbps (TMDS).

Only the TMDS link is currently supported.
Co-developed-by: Algea Cao <algea.cao@rock-chips.com>
Signed-off-by: Algea Cao <algea.cao@rock-chips.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
Link: https://lore.kernel.org/r/20240214-phy-hdptx-v4-2-e7974f46c1a7@collabora.comSigned-off-by: Vinod Koul <vkoul@kernel.org>