defconfig: arm64: msm: Enable MSM_DEBUG_LAR_UNLOCK flag.

Enable MSM_DEBUG_LAR_UNLOCK flag for to unlocking
Core Debug lock to allow capture upper 32 bits of
program counter for debugging purpose. msm8937_defconfig
is used for msm8937 target and msmcortex_defconfig is
used msmtitanium target.

Change-Id: I6f3353d83898c70c4e36ee1c1d404c93bad4e431
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>