rcar_gen3: plat: Add initial D3 support

Add R-Car D3 SoC platform specifics. Driver, PFC, QoS, DDR init code
will be added separately.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
diff --git a/drivers/renesas/rcar/board/board.h b/drivers/renesas/rcar/board/board.h
index 7bb2a06..05c4e8a 100644
--- a/drivers/renesas/rcar/board/board.h
+++ b/drivers/renesas/rcar/board/board.h
@@ -15,7 +15,8 @@
 #define BOARD_EBISU			(0x08)
 #define BOARD_STARTER_KIT_PRE		(0x0B)
 #define BOARD_EBISU_4D			(0x0DU)
-#define BOARD_UNKNOWN			(BOARD_EBISU_4D + 1U)
+#define BOARD_DRAAK			(0x0EU)
+#define BOARD_UNKNOWN			(BOARD_DRAAK + 1U)
 
 #define BOARD_REV_UNKNOWN		(0xFF)