dt-bindings: PCI: microchip,pcie-host: Allow dma-noncoherent

PolarFire SoC may be configured in a way that requires non-coherent DMA
handling. On RISC-V, buses are coherent by default & the dma-noncoherent
property is required to denote buses or devices that are non-coherent.

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Conor Dooley <[email protected]>
Signed-off-by: Daire McNamara <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>
Acked-by: Rob Herring <[email protected]>

Author: ConchuOD

Documentation/devicetree/bindings/pci/microchip,pcie-host.yaml

@@ -50,6 +50,8 @@ properties:
     items:
       pattern: '^fic[0-3]$'
 
+  dma-coherent: true
+
   ranges:
     minItems: 1
     maxItems: 3