ASoC: msm: check payload size before memory allocation

Buffer from mixer ctl or ADSP is composed of payload size and
actual payload. On a 32 bit platform, we could have an overflow
if payload size is below UINT_MAX while payload size + sizeof(struct)
is over UINT_MAX. Allocated memory size would be less than expected.
Check payload size against limit before memory allocation.

Change-Id: I0bf19ca7b8c93083177a21ad726122dc20f45551
Signed-off-by: Xiaojun Sang <xsang@codeaurora.org>