defconfig: Enable PANIC_ON_RECURSIVE_FAULT on sdxpoorwills target

Enable panic on recursive fault during do_exit() to collect the
important debug information leading to the fault.

Change-Id: I8c28a759019ec4b4887b3b4871ab17015709e7ce
Signed-off-by: Jeevan Shriram <jshriram@codeaurora.org>