mm-video: vidc: Adds NULL check for ETB buffer

Meta buffers needs to check against NULL address.
This change adds the check and returns error if NULL
buffer is queued to component.

CRs-Fixed: 590745

Change-Id: I8483e2b19e348c1c50bb4245bfd02419983b022e
mm-video: vdec: avoid set metadata after free buffer

In some use cases client frees output buffers before it gets
all FBD's, in this process component clears output buffer
structures it has for current session. Code dependent on
these structures results in crash if it executes after free
buffer. This change checks for such condition and avoids
the same.

CRs-fixed: 614669
Change-Id: Ia2b76425ebc49721beae2f02f5677d18dbff90a2
mm-video: vidc: vdec: set frame interlace based on firmware flag

Avoid depending on OMX Component h264 parser to read the mbaff
information. Instead the firmware will read mbaff information
and mark the fbd as interlace or progressive.

Change-Id: Icc68f9354f6baf4e5357af9379c05b851e5fecdd