mm-video: vdec: Get updated resolution along with output buffers

In case of smooth streaming the driver width/height might be
be updated multiple times before VIDIOC_G_FMT call was made to
the driver to get first updated width/height itself if the input
sequence has Header(w1xh1), AU data, Header(w2xh2), AU data and so on.
So client need to get the width/height along with output buffer itself
to update the display with correct width/height for every output frame
and skip calling VIDIOC_G_FMT to driver to get width/height.

Change-Id: I31992315a84350ddb7a43577dc70235ad9a8bc8f
mm-video: vidc: Avoid setting invalid timestamp of eos NAL

In arbitrary mode when eos NAL is appened at the end, while
coalscing with destination buffer, the actual timestamp is
overwritten with LLONG_MAX. This will lead to error log and
setting the flag V4L2_QCOM_BUF_TIMESTAMP_INVALID in driver,
which is not needed.

Change-Id: I87a63c4cb9d8259280b781cdd553050580809e8e