msm: vidc: Add support for dumping packets

Whenever we read and write from queues add support for logging the
packet being written or read.  As this produces heavy kmsg traffic, also
add a dynamic fallback option to use ftrace.  Output to ftrace can be
triggered by 'echo 1 > debugfs/msm_vidc/debug_output'

Change-Id: Ie221c60ab465605ede332ac7eaadfb4b26c19e01
Signed-off-by: Deva Ramasubramanian <dramasub@codeaurora.org>