devicetree: bindings: Document murata vendor prefix

Add Murata Manufacturing Co., Ltd. to the list of device tree
vendor prefixes.

Murata manufactures NTC (Negative Temperature Coefficient) based
Thermistors for small scale applications like Mobiles and PDAs.

Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>