arm64: dts: ti: k3-am68-sk: Enable DSI on DisplayPort-0

arm64: dts: ti: k3-am68-sk: Enable DSI on DisplayPort-0

Enable DSI support for AM68-SK platform.

Add DT node for DSI2eDP bridge. The DSI to eDP bridge is sn65dsi86
on the board.

Add the endpoint nodes to describe connection from:
DSS => DSI => SN65DSI86 bridge => DisplayPort-0

Signed-off-by: Jayesh Choudhary <j-choudhary@ti.com>
Tested-by: Harikrishna Shenoy <h-shenoy@ti.com>
Reviewed-by: Harikrishna Shenoy <h-shenoy@ti.com>
Reviewed-by: Udit Kumar <u-kumar1@ti.com>
Link: https://lore.kernel.org/r/20250716060114.52122-8-j-choudhary@ti.com
Signed-off-by: Nishanth Menon <nm@ti.com>