Add 'make flash' support with LPC21ISP (/tools)

[microbuilder]

make flash support should be added using lpc2isp in the /tools folder, assuming a standard FTDI cable or inexpensive USB to UART TTL cable as a transport mechanism.

This should be enabled for Windows and OS X as a minimum (ideally tested under Linux as well):

For example:

 lpc21isp -bin blinky_11u37.bin /dev/cu.usbserial-AD020SZ2 115200 48000

Chip IDs may need to be added for the various devices supported by this codebase, in particular the following devices (the device IDs are usually available in the datasheet but may need to be retrieved via a quick HW test):

• LPC11U24FBD48/401
• LPC11U37FBD48/401
• LPC11U37HFBD64/401
• LPC11U68JBD100
• LPC1347FBD48
• LPC1347FBD64
• LPC1347FHN33