dt-bindings: trivial-devices: Add xdpe11280

Add Infineon Multi-phase Digital Controller XDPE11280.

Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/81c0523ba790965a371d267bb1944652d80f5f72.1646214248.git.sylv@sylv.io
Signed-off-by: Guenter Roeck <linux@roeck-us.net>