dm: exynos: dts: Convert /include/ to #include

We should be consistent about this. The kernel has moved to #include
which breaks error reporting to some extent but does allow us to include
binding files.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/dts/exynos5420-smdk5420.dts b/arch/arm/dts/exynos5420-smdk5420.dts
index 1bc6256..6855027 100644
--- a/arch/arm/dts/exynos5420-smdk5420.dts
+++ b/arch/arm/dts/exynos5420-smdk5420.dts
@@ -8,7 +8,7 @@
  */
 
 /dts-v1/;
-/include/ "exynos54xx.dtsi"
+#include "exynos54xx.dtsi"
 
 / {
 	model = "SAMSUNG SMDK5420 board based on EXYNOS5420";