msm: vidc: Query deblocker parameters from cluster

Various fields of h264_db_control were left uninitialised before being
sent to the firmware.  As a result, due to poor luck, the resulting
encoded bitstreams were invalid as the alpha and beta were not in the
acceptable range of [-6, 6].  This commit fills the uninitialised values
with values obtained by querying the cluster.

Change-Id: Ic217d007239bc059302bdcdf2aebad1c9ca88244
Signed-off-by: Deva Ramasubramanian <dramasub@codeaurora.org>