ARM: dts: sb-som: introduce SB-SOM baseboard

CompuLab SB-SOM baseboard is a carrier board for multiple arm-based SoMs.
It currently supports (with minor adjustments to assembly) CM-T43, CM-T54,
and CM-QS600 modules. It is a building block in the SBC-T43 single board
computer, which consists of cm-t43 on top of sb-som-t43.

Signed-off-by: Nikita Kiryanov <[e-mail]>
Cc: Tony Lindgren <[e-mail]>
Cc: Benoit Cousson <[e-mail]>
Cc: Mark Rutland <[e-mail]>
Cc: Pawel Moll <[e-mail]>
Cc: Igor Grinberg <[e-mail]>
Cc: Dmitry Lifshitz <[e-mail]>
Cc: Ian Campbell <[e-mail]>
Acked-by: Rob Herring <[e-mail]>
Signed-off-by: Tony Lindgren <[e-mail]>

Documentation/devicetree/bindings/arm/compulab-boards.txt

···
+CompuLab SB-SOM is a multi-module baseboard capable of carrying CM-T43, CM-T54,
+and CM-QS600 modules with minor modifications to the SB-SOM assembly.
+
+Required root node properties:
+    - compatible = should be "compulab,sb-som"

Documentation/devicetree/bindings/display/panel/startek,startek-kd050c.txt

···
+Startek Electronic Technology Co. KD050C 5.0" WVGA TFT LCD panel
+
+Required properties:
+- compatible: should be "startek,startek-kd050c"

Documentation/devicetree/bindings/vendor-prefixes.txt

···
 spansion	Spansion Inc.
 sprd	Spreadtrum Communications Inc.
 st	STMicroelectronics
+startek	Startek
 ste	ST-Ericsson
 stericsson	ST-Ericsson
 synology	Synology, Inc.

arch/arm/boot/dts/compulab-sb-som.dtsi

···
+/*
+ * Copyright (C) 2015 CompuLab, Ltd. - http://www.compulab.co.il/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/ {
+	model = "CompuLab SB-SOM";
+	compatible = "compulab,sb-som";
+
+	vsb_3v3: fixedregulator-v3_3 {
+		compatible = "regulator-fixed";
+		regulator-name = "vsb_3v3";
+		regulator-min-microvolt = <3300000>;
+		regulator-max-microvolt = <3300000>;
+		regulator-always-on;
+		enable-active-high;
+	};
+
+	lcd0: display {
+		compatible = "startek,startek-kd050c", "panel-dpi";
+		label = "lcd";
+
+		panel-timing {
+			clock-frequency = <33000000>;
+			hactive = <800>;
+			vactive = <480>;
+			hfront-porch = <40>;
+			hback-porch = <40>;
+			hsync-len = <43>;
+			vback-porch = <29>;
+			vfront-porch = <13>;
+			vsync-len = <3>;
+			hsync-active = <0>;
+			vsync-active = <0>;
+			de-active = <1>;
+			pixelclk-active = <1>;
+		};
+	};
+};