dt-bindings: ata: ahci-da850: Convert to dtschema

Convert the ahci-da850 bindings to DT schema.

Signed-off-by: Animesh Agarwal <animeshagarwal28@gmail.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>