stm32mp1: introduce STM32MP1 discovery boards

Add the device tree files to support the 2 discovery boards: DK1 & DK2.

Change-Id: I90b4797dc69bd0aab1b643a72c932ead48a03c1f
Signed-off-by: Yann Gautier <yann.gautier@st.com>
diff --git a/fdts/stm32mp157c-dk2.dts b/fdts/stm32mp157c-dk2.dts
new file mode 100644
index 0000000..fdcf4c8
--- /dev/null
+++ b/fdts/stm32mp157c-dk2.dts
@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
+/*
+ * Copyright (C) STMicroelectronics 2018 - All Rights Reserved
+ * Author: Alexandre Torgue <alexandre.torgue@st.com>.
+ */
+
+/dts-v1/;
+
+#include "stm32mp157a-dk1.dts"
+
+/ {
+	model = "STMicroelectronics STM32MP157C-DK2 Discovery Board";
+	compatible = "st,stm32mp157c-dk2", "st,stm32mp157";
+
+};
+