msm: ADSPRPC: Size check before allocating memory from DMA

For allocating memory from DMA we need to do a size check.
This validation is required to avoid any improper paging
request. We already have the range in which the size is
expected to be.

Change-Id: I72919a8807a7e3bacb7f8353a2aabb8cc6c19f0f
Acked-by: Ekansh Gupta <ekangupt@qti.qualcomm.com>
Signed-off-by: Jeya R <jeyr@codeaurora.org>