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: configure and set hier-p layers

Firmware requires the max number of hier-p layers
to be used during the encode session to be set
in load resources state. Without this change,
firmware will not enable hier-p encoding. Also
switch to using HFI_PROPERTY_CONFIG_VENC_HIER_P_ENH_LAYER
to set the number of hier-p layers.

Change-Id: I1fbf835acdb7d0a06d33cf9c2d038fb87c10010d
Signed-off-by: Arun Menon <avmenon@codeaurora.org>