the LEDs (2 of them) were connected to the same pins on all
boards, up to the octsim-tester.
to be able to have board specific LEDs the definitions have moved
from common to the each board.
at the same time I added a bit of documentation what the LEDs are
used for.
Change-Id: I3226a9187a8d0b657ccf5dcd8f3586b2578f96d2
This is a general purpose evaluation board, and it makes sense to
support it particularly for the DFU bootloader.
Change-Id: I85aea8f1441158f991493c5fc767fdcad405545e