ARM: renesas: Add Renesas R8A779H0 V4M Gray Hawk board code

Add board code for the Renesas R8A779H0 V4M Gray Hawk board.

Signed-off-by: Hai Pham <hai.pham.ud@renesas.com>
diff --git a/board/renesas/grayhawk/Kconfig b/board/renesas/grayhawk/Kconfig
new file mode 100644
index 0000000..97621a3
--- /dev/null
+++ b/board/renesas/grayhawk/Kconfig
@@ -0,0 +1,15 @@
+if TARGET_GRAYHAWK
+
+config SYS_SOC
+	default "rmobile"
+
+config SYS_BOARD
+	default "grayhawk"
+
+config SYS_VENDOR
+	default "renesas"
+
+config SYS_CONFIG_NAME
+	default "grayhawk"
+
+endif