ASoC: msm: q6dspv2: use correct variable type to store ION buff size

The size of the physical memory allocated for ION buffers
are of type size_t. Change updates the type of variables
sent to ION drivers to size_t to avoid any mismatch.

Change-Id: I3d33ed922b979652c64027e6f1c6f0a8ed4850a3
Signed-off-by: Banajit Goswami <bgoswami@codeaurora.org>