usb: dt-bindings: ti,twl6030-usb: convert to DT schema

usb: dt-bindings: ti,twl6030-usb: convert to DT schema

Convert the legacy TXT binding for the TWL6030 USB module
to the modern YAML DT schema format. This adds formal validation
and improves documentation using a conditional schema.

The legacy twlxxxx-usb.txt file is no longer needed and is removed.

Signed-off-by: Jihed Chaibi <jihed.chaibi.dev@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20250824112338.64953-3-jihed.chaibi.dev@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>