dt-bindings: remoteproc: Drop redundant $ref of firmware-name property

The DT schema core defines the type ($ref) of 'firmware-name' property
as string-array, so individual schemas do not need to.  They also should
not redefine it to a single string, but instead just set number of
expected firmware names.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260712145718.126492-2-krzysztof.kozlowski@oss.qualcomm.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

Documentation/devicetree/bindings/remoteproc/amlogic,meson-mx-ao-arc.yaml

@@ -25,7 +25,7 @@ properties:
       - const: amlogic,meson-mx-ao-arc
 
   firmware-name:
-    $ref: /schemas/types.yaml#/definitions/string
+    maxItems: 1
     description:
       The name of the firmware which should be loaded for this remote
       processor.

Documentation/devicetree/bindings/remoteproc/ti,pru-consumer.yaml

@@ -30,7 +30,6 @@ properties:
       maxItems: 1
 
   firmware-name:
-    $ref: /schemas/types.yaml#/definitions/string-array
     minItems: 1
     maxItems: 6
     description: |