[AVR32] Update defconfigs

Update defconfigs for ATNGW100 and ATSTK1002. This will enable the
SLUB allocator by default on both, and will enable NFS root on
ATSTK1002 (ATNGW100 had it enabled before.)

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