arm64: dts: ti: k3-am69-sk: Add DP and HDMI support

AM69 starter kit features an HDMI port and an eDP port.

Add assigned clocks for DSS, DT node for DisplayPort PHY,
pinmux for HDMI hotplug and power down, mcu_i2c1 and dss_vout
for HDMI.
Also enable Serdes4 settings for DP display.

Add the endpoint nodes to describe connection from:
DSS => MHDP => DisplayPort connector
DSS => TI TFP410 DPI-to-DVI Bridge => HDMI connector

Signed-off-by: Dasnavis Sabiya <sabiya.d@ti.com>
[j-choudhary@ti.com: Fix dvi-bridge, dss, mhdp and serdes-refclk]
Signed-off-by: Jayesh Choudhary <j-choudhary@ti.com>
Reviewed-by: Aradhya Bhatia <a-bhatia1@ti.com>
Reviewed-by: Roger Quadros <rogerq@kernel.org>
Link: https://lore.kernel.org/r/20231019054022.175163-6-j-choudhary@ti.com


Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>