ARM: dts: renesas: Add RZ/A1 GR-Peach board

Add board code and DTs for Renesas RZ/A1 SoC-based GR-Peach,
which is a cheap development platform with RZ/A1H SoC. The
DTs are imported from Linux 5.0.11, commit d5a2675b207d .

Currently supported are UART, ethernet and RPC SPI. The board
can be booted from RPC SPI by writing the u-boot.bin binary
to the beginning of the SPI NOR, e.g. using the "sf" command.
The board can also be booted via JTAG by setting text base to
0x20020000, loading u-boot.bin there via JTAG and executing it
from that address.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Chris Brandt <chris.brandt@renesas.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
diff --git a/board/renesas/grpeach/Kconfig b/board/renesas/grpeach/Kconfig
new file mode 100644
index 0000000..00dc496
--- /dev/null
+++ b/board/renesas/grpeach/Kconfig
@@ -0,0 +1,12 @@
+if TARGET_GRPEACH
+
+config SYS_BOARD
+	default "grpeach"
+
+config SYS_VENDOR
+	default "renesas"
+
+config SYS_CONFIG_NAME
+	default "grpeach"
+
+endif