ARM: dts: omap3: correct the format of u16 values for tsc2046 node

In tsc2046 touch driver, the values such as ti,x-min is defined as a u16
value. the driver use API of_property_read_u16() read the value. For these
u16 value, the dts entry should be like:
	property = /bits/ 16 <0x5000>;
This describes the property as a u16 value.

Signed-off-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>