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: I9937c0249ec10553efdf7bb2230f48ea8e8a28cd
Signed-off-by: Arun Kumar Neelakantam <aneela@codeaurora.org>