dt-bindings: clock: samsung: fix header path in example

The proper header is exynos4.h:

    samsung,exynos4412-isp-clock.example.dts:19:18: fatal error: dt-bindings/clock/exynos4412.h: No such file or directory

Fixes: 7ac61578 ("dt-bindings: clock: samsung: convert Exynos4 to dtschema")
Reported-by: Stephen Boyd <sboyd@kernel.org>
Reported-by: Rob Herring <robh+dt@kernel.org>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20210831130643.83249-1-krzysztof.kozlowski@canonical.comAcked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

Documentation/devicetree/bindings/clock/samsung,exynos4412-isp-clock.yaml

@@ -52,7 +52,7 @@ additionalProperties: false
 
 examples:
   - |
-    #include <dt-bindings/clock/exynos4412.h>
+    #include <dt-bindings/clock/exynos4.h>
     clock-controller@10048000 {
         compatible = "samsung,exynos4412-isp-clock";
         reg = <0x10048000 0x1000>;