vidc: 720p: Fix for H264 thumbnail generation

Core is sending non frame data error for SPS and
PPS, which is communicated as a fatal error to
the component in case of idr only mode. Fixed this
by sending it as a bit stream error.

Change-Id: I79b1fb45857b3b18fa84f17dca3d8a8a2fbb1d2b
CRs-Fixed: 326563
Signed-off-by: Rajeshwar Kurapaty <rkurapat@codeaurora.org>