defconfig: arm: msm: Enable CONFIG_MSM_SMD_DEBUG flag for msmcortex

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: I0d82482bdc76ed36d0e6463e63545590c116654d
Signed-off-by: Arun Kumar Neelakantam <aneela@codeaurora.org>