spi: dt-bindings: cleanup examples - indentation, lowercase hex

Cleanup examples:
 - use 4-space indentation (for cases when it is neither 4 not 2 space),
 - drop redundant blank lines,
 - use lowercase hex.

No functional impact except adjusting to preferred coding style.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> # renesas
Reviewed-by: Andrew Jeffery <andrew@aj.id.au> # aspeed
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org> # meson
Link: https://lore.kernel.org/r/20230124083342.34869-2-krzysztof.kozlowski@linaro.orgSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/spi/qcom,spi-qcom-qspi.yaml

@@ -87,7 +87,6 @@ examples:
                 spi-tx-bus-width = <2>;
                 spi-rx-bus-width = <2>;
             };
-
         };
     };
 ...

Documentation/devicetree/bindings/spi/spi-sunplus-sp7021.yaml

@@ -59,9 +59,9 @@ unevaluatedProperties: false
 examples:
   - |
     #include <dt-bindings/interrupt-controller/irq.h>
-    spi@9C002D80 {
+    spi@9c002d80 {
         compatible = "sunplus,sp7021-spi";
-        reg = <0x9C002D80 0x80>, <0x9C002E00 0x80>;
+        reg = <0x9c002d80 0x80>, <0x9c002e00 0x80>;
         reg-names = "master", "slave";
         interrupt-parent = <&intc>;
         interrupt-names = "dma_w",

Documentation/devicetree/bindings/spi/st,stm32-spi.yaml

@@ -95,7 +95,6 @@ examples:
                <&dmamux1 1 40 0x400 0x05>;
         dma-names = "rx", "tx";
         cs-gpios = <&gpioa 11 0>;
-
     };
 
 ...