msm: vidc: add control to enable Hierarchical P num layers

This change will enable firmware to perform Hierarchical
video encoding for P frames. Hierarchical video encoding is
used to improve error resilience and temporal scalability.
The encoded frames are logically organized in to multiple
layers with frames in one layer referencing only frames
from lower layers. The lowest layer, i.e. base layer, is
the only exception.

Change-Id: Ie30e6d075b76b3337ec895584cf1f3be9f4bb6c6
Signed-off-by: Arun Menon <avmenon@codeaurora.org>
msm: vidc: Add description of LTR Extradata

The missing string descriptor caused a mismatch in array sizes
causing the v4l2 control framework make an out of bounds access.

Change-Id: I9a9f64e16ca95163d800702d94528833f5892537
Signed-off-by: Deva Ramasubramanian <dramasub@codeaurora.org>
msm: vidc: Query the core on VIDIOC_G_FMT

Previously we only queried the core for buffer requirements in
VIDIOC_REQBUFS, and relied on that information in _G_FMT.  However,
there's no expectation that the client calls _REQBUFS before _G_FMT,
which leads to stale information being returned as part of _G_FMT.

As such, always retreive fresh info from the core for either ioctl.

Change-Id: Ife94343f4bd4f62da7f2bef4266076ceed409bca
Signed-off-by: Deva Ramasubramanian <dramasub@codeaurora.org>
msm: vidc: detect mbaff information from firmware

Firmware will set the FBD flags if mbaff interface
is detected for decoded video bitstream. Previously
the mbaff information was parsed in the v4l2 video
client, but now firmware parses and sends the information.

Change-Id: Ic557cdb7bf49aab3eb29a3f3aa3e363bf7223a36
Signed-off-by: Arun Menon <avmenon@codeaurora.org>