mm-video-v4l2: venc: Change QBUF and STREAM_ON call sequence

By calling STREAM_ON after QBUF, and meanwhile if there is
any buffer requirements query, there is a chance that queued
buffer will be ignored by driver. Hence changing the QBUF and
STREAM_ON sequence.

CRs-Fixed: 2065953

Author : Manikanta Kanamarlapudi <kmanikan@codeaurora.org>

Bug: 62602083
Test: make vts
      vts-tradefed run vts -m VtsHalMediaOmxV1_0Host
Merged-In: I0ec277a5b245d7b4aa343030ca74a2d86d7d91c1
Change-Id: I0ec277a5b245d7b4aa343030ca74a2d86d7d91c1