Replace dts includes with C preprocessor syntax

Using the /include/ syntax, the include was evaluated by dtc, only after running
the preprocessor, therefore the .dtsi files were not preprocessed. This patch
adds the #include syntax instead. Evaluating this and preprocessing the files
now happens in a single step, done by the C preprocessor.

Change-Id: I6d0104b6274316fc736e84973502a4d6c2c9d6e0
Signed-off-by: Balint Dobszay <balint.dobszay@arm.com>
diff --git a/fdts/fvp-base-gicv3-psci-1t.dts b/fdts/fvp-base-gicv3-psci-1t.dts
index 36fbd44..3c82f7b 100644
--- a/fdts/fvp-base-gicv3-psci-1t.dts
+++ b/fdts/fvp-base-gicv3-psci-1t.dts
@@ -1,12 +1,12 @@
 /*
- * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2017-2020, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
 /dts-v1/;
 
-/include/ "fvp-base-gicv3-psci-common.dtsi"
+#include "fvp-base-gicv3-psci-common.dtsi"
 
 &CPU0 {
 	reg = <0x0 0x0>;