ARM: dts: Add am335x-evmsk.dts

Add AM335X EVM-SK device tree source (am335x-sk.dts) file to use
the am33xx.dtsi SoC file, along with the memory node information.

Also adds support for tps65910 regulator and lis331dlh accelerometer.
Following drivers/functionality were tested on AM335x-EVM-SK.
* I2C
* TPS65910 regulators
* lis331dlh accelerometer

AM335x EVM Starter Kit details can be accessed from:
http://www.ti.com/tool/tmdssk3358



Signed-off-by: AnilKumar Ch <anilkumar@ti.com>
Signed-off-by: Benoit Cousson <b-cousson@ti.com>