msm: vidc_3x: Add support for decoder/encoder STOP command

Decoder/encoder STOP command is to signal HW that this is the EOS
buffer. HW returns all the pending ETB's and FTB's. one of
the ETB_DONE's will have EOS flag back to client. With this,
driver don't need to support zero_bytes_used input buffers.

Change-Id: I465740aadaa30c62235894bc8602a6532a1925de
Signed-off-by: Mansur Alisha Shaik <mansur@codeaurora.org>