msm: vidc: Fix metadata buffer size issue

- Metadata buffer size is being set to zero when
  client calls set buffer requirements to video driver.
  This change fix it by properly assigning the
  metadata buffer size to video driver.
- When continuous mode enabled, do not get min_dpb
  from resource tracker for non-H264 codecs,
  for H264 codec get min_dpb from resource tracker.

Change-Id: Ie16bc47605edc6f67dbf3ae77290d4d764c5c613
Signed-off-by: Maheshwar Ajja <majja@codeaurora.org>