Soc: msm: qdsp6v2: Fix invalid params handling

Alloc and free apis should sanity check all input params.
If allocation fails set client and ion handle to NULL.

Change-Id: Ide3bd782eb90ee8b033e39de232929a1ca7174b7
Signed-off-by: Gopikrishnaiah Anandan <agopik@codeaurora.org>
Signed-off-by: flar2 <asegaert@gmail.com>