board: st: add generic board for STM32MP1 family

Add first support for STM32MP157C-ED1 board with "Basic" boot chain
1/ Boot Rom: load SPL with STM32 image header in SYSRAM
2/ SPL: power up and initialize the DDR and load U-Boot image
        from SDCARD in DDR
3/ U-Boot: search and load extlinux.conf in SDCARD
           (DISTRO activated)

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
diff --git a/board/st/stm32mp1/Makefile b/board/st/stm32mp1/Makefile
new file mode 100644
index 0000000..eaf45b7
--- /dev/null
+++ b/board/st/stm32mp1/Makefile
@@ -0,0 +1,13 @@
+#
+# Copyright (C) 2018, STMicroelectronics - All Rights Reserved
+#
+# SPDX-License-Identifier:	GPL-2.0+	BSD-3-Clause
+#
+
+ifdef CONFIG_SPL_BUILD
+obj-y += spl.o
+else
+obj-y += stm32mp1.o
+endif
+
+obj-y += board.o