ARM: dts: am335x: Add initial support for ICEv2 board

ARM: dts: am335x: Add initial support for ICEv2 board

TI's Industrial Communication Engine EVM is a low cost hardware mainly
developed for industrial communication type applications using serial
or Ethernet based interfaces. This platform features TI's AM3359 with
800MHz single core Cortex-A8 processor, 256MB DDR3, 64MB SPI flash,
8MB NOR Flash, mmc, usb, can, dual Ethernet ports.

For more information, look at HW user guide[1], Data manual[2].

Just add basic support for the moment.

[1] http://processors.wiki.ti.com/index.php/AM335x_Industrial_Communication_Engine_EVM_Rev2_1_HW_User_Guide
[2] http://www.ti.com/lit/ds/symlink/am3359.pdf

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>