ASoC: msm: qdsp6v2: Correct buffer size alignment while memory map

Buffer size needs to be aligned at 4K byte boundary
while sending memory map command to the Q6 DSP, otherwise
DSP would return failure as response to the memory map
command failing audio session.

CRs-fixed: 830118
Change-Id: I28dd85a0bdfde5ef42ee5b6ae43fb506fdbbe310
Signed-off-by: Phani Kumar Uppalapati <phaniu@codeaurora.org>