input: sensor: Add device tree support for stk3x1x

Add device tree parser and binding document for Sensortek stk3x1x
series ambient light/proximity sensor.

Change-Id: I8e553da2856ecd42629a409347659e71dcdd8f2f
Signed-off-by: Bingzhe Cai <bingzhec@codeaurora.org>
diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt
index a3a3807..527c50c 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.txt
+++ b/Documentation/devicetree/bindings/vendor-prefixes.txt
@@ -42,6 +42,7 @@
 samsung	Samsung Semiconductor
 sbs	Smart Battery System
 schindler	Schindler
+stk	Sensortek Technology Corporation.(formerly Sitronix Technology Co., Ltd.)
 shinetech	Shine Tech Corporation, Ltd.
 sil	Silicon Image
 simtek