dt-bindings: ata: ahci-platform: Convert DT bindings to yaml

Create a yaml file for dtbs_check from the old txt binding.

Signed-off-by: Frank Wunderlich <frank-w@public-files.de>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220311210357.222830-2-linux@fw-web.de