board: schneider: add RZN1 board support

Add support for Schneider Electric RZ/N1D and RZ/N1S boards, which
are based on the Reneasas RZ/N1 SoC devices.

The intention is to support both boards using a single defconfig, and to
handle the differences at runtime.

Signed-off-by: Ralph Siemsen <ralph.siemsen@linaro.org>
Reviewed-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
diff --git a/board/schneider/rzn1-snarc/Kconfig b/board/schneider/rzn1-snarc/Kconfig
new file mode 100644
index 0000000..1c1c235
--- /dev/null
+++ b/board/schneider/rzn1-snarc/Kconfig
@@ -0,0 +1,18 @@
+if TARGET_SCHNEIDER_RZN1
+
+config TEXT_BASE
+	default 0x20040000
+
+config SYS_MONITOR_LEN
+	default 524288
+
+config SYS_BOARD
+	default "rzn1-snarc"
+
+config SYS_VENDOR
+	default "schneider"
+
+config SYS_CONFIG_NAME
+	default "rzn1-snarc"
+
+endif