msm: adsprpc: Free dma handles in RPC call with no parameters

Currently dma handles are not freed in the RPC call with no parameters.
This will cause fastrpc driver to hold the memory of the dma handle, that
is freed in both DSP and application user space. Free dma handles even
in the RPC call with no parameters.

Change-Id: Ica5bfc98edc07b77f79bfaf75630508b8c9ee1af
Signed-off-by: Himateja Reddy <hmreddy@codeaurora.org>