msm: vidc: add support to set VP8 QP range

QP range differs from codec to codec. This change adds support
for VP8 QP min and max range.

Change-Id: Ia44cf885a8b6f71b7eef51076968021ae68d7a7e
CRs-Fixed: 578892
Signed-off-by: Jorge Solano Altamirano <jsolano@codeaurora.org>