arm64: dts: ti: k3-am62x-sk-common: Add HDMI support

arm64: dts: ti: k3-am62x-sk-common: Add HDMI support

The DSS outputs DPI signals via its second video port (VP2). The DPI
output from DSS is 24 bits (RGB888) and is forwarded to an HDMI
transmitter (SIL9022) on the board.

Add pinmux info for DSS DPI output.

Add DT nodes for SIL9022 HDMI transmitter (TX), and the HDMI connector
on the AM625 SK and AM62-LP SK platforms.

Additionally, connect the output of DSS (VP2) with input of the HDMI TX,
and the output of HDMI TX to the input of the HDMI connector.

Signed-off-by: Aradhya Bhatia <a-bhatia1@ti.com>
Link: https://lore.kernel.org/r/20230809084559.17322-4-a-bhatia1@ti.com
Signed-off-by: Nishanth Menon <nm@ti.com>