dt-bindings: gpu: drop unneeded quotes

Cleanup bindings dropping unneeded quotes. Once all these are fixed,
checking for this can be enabled in yamllint.

Signed-off-by: Krzysztof Kozlowski <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Rob Herring <[e-mail]>

Documentation/devicetree/bindings/gpu/arm,mali-bifrost.yaml

···
     const: 2
 
   dynamic-power-coefficient:
-    $ref: '/schemas/types.yaml#/definitions/uint32'
+    $ref: /schemas/types.yaml#/definitions/uint32
     description:
       A u32 value that represents the running time dynamic
       power coefficient in units of uW/MHz/V^2. The

Documentation/devicetree/bindings/gpu/arm,mali-midgard.yaml

···
   dma-coherent: true
 
   dynamic-power-coefficient:
-    $ref: '/schemas/types.yaml#/definitions/uint32'
+    $ref: /schemas/types.yaml#/definitions/uint32
     description:
       A u32 value that represents the running time dynamic
       power coefficient in units of uW/MHz/V^2. The