msm: vidc: Update default CR value for recon buffers

Recon stats are send as zero for b-frames (non-reference frames).
Earlier, buffer CR (Compression Ratio) is set to possible minimum
CR when firmware stats are zero, which results in bus to vote for
high bandwidth.

Update recon buffer default CR value to zero.This fix will use
the recon stats from the list updated with past frames to compute
recon CR, when the stats from firmware are zero.

Change-Id: I7e8842de2793cc8285689a2768222034ee416eb0
Signed-off-by: Priyanka Gujjula <pgujjula@codeaurora.org>