dt-bindings: display: ti: Add support for am62a7 dss

The DSS controller on TI's AM62A7 SoC is an update from that on TI's
AM625 SoC. Like the DSS in AM625, the DSS in this SoC has 2 video
pipelines, but unlike the former, the latter only has one output port on
VP2 to service DPI display sinks.

Add the new controller's compatible.

Signed-off-by: Aradhya Bhatia <a-bhatia1@ti.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Link: https://lore.kernel.org/r/20231108171619.978438-2-a-bhatia1@ti.com


Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>