ARM: dts: mxs: support i.MX28 Amarula rmm board

The board includes the following resources:
 - 256 Mbytes NAND Flash
 - 128 Mbytes DRAM DDR2
 - CAN
 - USB 2.0 high-speed/full-speed
 - Ethernet MAC

Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>