defconfig: lahaina: Enable PRIORITIZE_OOM_TASKS

Enable support for prioritizing the tasks which are killed by the OOM
killer in order to ensure that higher priority tasks (oom_score_adj < 0)
aren’t killed unless there are no other low priority tasks to consider.

Change-Id: I32a82c65146a3c9679e5e7f69ce36aaf1de9155a
Signed-off-by: Liam Mark <lmark@codeaurora.org>