dt-bindings: dma: Drop undocumented examples

The compatibles "ti,omap-sdma" and "ti,dra7-dma-crossbar" aren't documented
by a schema which causes warnings:

Documentation/devicetree/bindings/dma/dma-controller.example.dtb: /example-0/dma-controller@48000000: failed to match any schema with compatible: ['ti,omap-sdma']
Documentation/devicetree/bindings/dma/dma-router.example.dtb: /example-0/dma-router@4a002b78: failed to match any schema with compatible: ['ti,dra7-dma-crossbar']

As no one has cared to fix them, just drop them.

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

Documentation/devicetree/bindings/dma/dma-controller.yaml

···
 
 additionalProperties: true
 
-examples:
-  - |
-    dma: dma-controller@48000000 {
-        compatible = "ti,omap-sdma";
-        reg = <0x48000000 0x1000>;
-        interrupts = <0 12 0x4>,
-                     <0 13 0x4>,
-                     <0 14 0x4>,
-                     <0 15 0x4>;
-        #dma-cells = <1>;
-        dma-channels = <32>;
-        dma-requests = <127>;
-        dma-channel-mask = <0xfffe>;
-    };
-
 ...

Documentation/devicetree/bindings/dma/dma-router.yaml

···
 
 additionalProperties: true
 
-examples:
-  - |
-    sdma_xbar: dma-router@4a002b78 {
-        compatible = "ti,dra7-dma-crossbar";
-        reg = <0x4a002b78 0xfc>;
-        #dma-cells = <1>;
-        dma-requests = <205>;
-        ti,dma-safe-map = <0>;
-        dma-masters = <&sdma>;
-    };
-
 ...