add print kernel performance function.

usage:
./test-cl-image -t demo -f nv12 -i input.nv12 -o output.nv12 -p 1000

After this it will run demo cl kernel 1000 times and print performance
info and terminate process. If you don't want to use this function,
just don't write '-p 1000' in your cmdline.

Signed-off-by: Wind Yuan <feng.yuan@intel.com>
2 files changed