Added new platform for LPC1768

This is a port of LPC1768 and a bi-directional DC to DC conversion platform with Ethernet interface. The LPC1768 is a Cortex-M3 based microcontroller for embedded applications. Features include 512 kB of flash memory, 64 kB of data memory, Ethernet MAC, 4 UARTs, 8-channel 12-bit ADC, 10-bit DAC and so on. For more information, please refer to NXP webpage: 
http://www.nxp.com/products/microcontrollers/cortex_m3/LPC1768FBD100.html

This port is the result of several development iterations by master students at KTH (Royal Institute of Technology) and it can be part of a Microgrid, a concept in which smart power management system is achieved by utilizing IoT technologies. This port at the minimum features system initialization and configuration, Ethernet communication (LPC1768 has a built-in ethernet module) as well as UART interface for flash/debug.

PCB design of this platform will be publicly available via http://ttaportal.org shortly as well as technical report and comprehensive guide for anyone who will be interested in this platform. Also LPC1786 has been around for some years and there are publicly available platforms based on this microcontroller.

Following Contiki applications have been tested successfully with this port:
helloworld:
    In /example/hello-world/, uncomment UIP_CONF_IPV6=1 and set TARGET=bi-dcdc
er-rest-example:
    In /example/er-rest-example/, set TARGET=bi-dcdc

KTH telecommunication lab will be in charge of maintaining this port and corresponding applications.