defconfig: arm: msm: Enable CONFIG_MSM_SMD_DEBUG flag for msm8937

Enable the CONFIG_MSM_SMD_DEBUG flag to support for debugging SMD
and SMSM communication between apps and other processors in the SoC.

Change-Id: I3dbb20436e0a6300189aec633604d24074924619
Signed-off-by: Arun Kumar Neelakantam <aneela@codeaurora.org>