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/Makefile b/board/renesas/grayhawk/Makefile
new file mode 100644
index 0000000..9c5b8c9
--- /dev/null
+++ b/board/renesas/grayhawk/Makefile
@@ -0,0 +1,9 @@
+#
+# board/renesas/grayhawk/Makefile
+#
+# Copyright (C) 2023 Renesas Electronics Corp.
+#
+# SPDX-License-Identifier: GPL-2.0+
+#
+
+obj-y	:= grayhawk.o ../rcar-common/common.o