defconfig: msm: enable Linux Kernel Dump Test Tool

This feature enables to test Privilege Access Never (PAN) feature from
user space through ACCESS_USERSPACE interface supported by LKDTM.
Enable it only in debug defconfig.

Change-Id: Ie8c9c3225acc72f05ecba039cd552eb1ad912631
Signed-off-by: Ramakrishna Gottimukkula <rgottimu@codeaurora.org>