spi: dt-bindings: samsung: drop cs-gpios

Remove cs-gpios because it is already mentioned by common
spi-controller.yaml.

Signed-off-by: Krzysztof Kozlowski <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mark Brown <[email protected]>

Author: krzk

Documentation/devicetree/bindings/spi/samsung,spi.yaml

@@ -35,8 +35,6 @@ properties:
     minItems: 2
     maxItems: 3
 
-  cs-gpios: true
-
   dmas:
     minItems: 2
     maxItems: 2