msm: vidc: add input parameter checks to exported functions

Check for invalid null parameter passed to functions

CRs-Fixed: 606467
Change-Id: I860ca3d69d8705c7b3d6f27f9504b567be5aeea3
Signed-off-by: Jorge Solano Altamirano <jsolano@codeaurora.org>
Merge "msm: vidc: add input parameter checks to exported functions"