serial-arc: switch to DM

Now when all infrastructure in ARC is ready for it let's switch ARC UART
to driver model.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Simon Glass <sjg@chromium.org>

arch/arc/dts/Makefile

@@ -0,0 +1,11 @@
+dtb-$(CONFIG_TARGET_ARCANGEL4) +=  arcangel4.dtb
+
+targets += $(dtb-y)
+
+DTC_FLAGS += -R 4 -p 0x1000
+
+PHONY += dtbs
+dtbs: $(addprefix $(obj)/, $(dtb-y))
+	@:
+
+clean-files := *.dtb

arch/arc/dts/arcangel4.dts

@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2015 Synopsys, Inc. (www.synopsys.com)
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+/dts-v1/;
+
+#include "skeleton.dtsi"
+
+/ {
+	#address-cells = <1>;
+	#size-cells = <1>;
+
+	aliases {
+		console = &arcuart0;
+	};
+
+	arcuart0: serial@0xc0fc1000 {
+		compatible = "snps,arc-uart";
+		reg = <0xc0fc1000 0x100>;
+		clock-frequency = <80000000>;
+	};
+
+};

arch/arc/dts/skeleton.dtsi

@@ -0,0 +1,13 @@
+/*
+ * Skeleton device tree; the bare minimum needed to boot; just include and
+ * add a compatible value.  The bootloader will typically populate the memory
+ * node.
+ */
+
+/ {
+	#address-cells = <1>;
+	#size-cells = <1>;
+	chosen { };
+	aliases { };
+	memory { device_type = "memory"; reg = <0 0>; };
+};