dt-bindings: ata: ahci-platform: Move dma-coherent to sata-common.yaml

Seeing doubtfully any SATA device working without embedded DMA engine
let's permit the device nodes being equipped with the dma-coherent
property in case if the platform is capable of cache-coherent DMAs.

As a side-effect we can drop the explicit dma-coherent property definition
from the particular device schemas. Currently it concerns the Broadcom
SATA AHCI controller only.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

Documentation/devicetree/bindings/ata/ahci-platform.yaml

@@ -87,8 +87,6 @@ properties:
     description:
       regulator for AHCI controller
 
-  dma-coherent: true
-
   phy-supply:
     description:
       regulator for PHY power

Documentation/devicetree/bindings/ata/brcm,sata-brcm.yaml

@@ -41,8 +41,6 @@ properties:
   interrupts:
     maxItems: 1
 
-  dma-coherent: true
-
 if:
   properties:
     compatible:

Documentation/devicetree/bindings/ata/sata-common.yaml

@@ -31,6 +31,8 @@ properties:
   "#size-cells":
     const: 0
 
+  dma-coherent: true
+
 patternProperties:
   "^sata-port@[0-9a-e]$":
     description: |