msm: qdsp6v2: memset stack buffer allocation.

This is needed to avoid garbage data in uninitialized variables.

Change-Id: Id5921e369055d846b990380be6355ad464518a10
CRs-Fixed: 554301
Signed-off-by: Yeleswarapu, Nagaradhesh <nagaradh@codeaurora.org>
Signed-off-by: Mohammad Johny Shaik <mjshai@codeaurora.org>