Finish up support for the ATSTK1000/ATSTK1002 boards

Add atstk1002_config target to Makefile and move the AVR32 section
down below Blackfin so that it doesn't end up in the middle of
MIPS.

Drop the autogenerated linker script thing for now. Will have to
revisit how to handle chips with different flash and RAM layout
later.

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>