msm: vidc: Allow venus_hfi.c to accept a batch of frames

This is a groundwork commit to introduce a public API that allows the
client to provide an array of input and output buffers.  The advantage
of this API is that all commands to the hardware is consolidated into a
single interrupt.

Change-Id: I6720b42161918d7efb4514b0d083ab8a11672362
Signed-off-by: Deva Ramasubramanian <dramasub@codeaurora.org>