dt-bindings: trivial-devices: Add Infineon TDA38640 Voltage Regulator

Infineon TDA38640 is PMBUS compliant voltage regulator.

Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230124202317.3704963-1-Naresh.Solanki@9elements.com


Signed-off-by: Guenter Roeck <linux@roeck-us.net>