common: Enable log system

Use export LIBYAMI_LOG_LEVEL=log_level to set the control flag, export LIBYAMI_TRACE=log_file to set the file location

Signed-off-by: Tang Xin <xin.t.tang@intel.com>
however, we don't have better choice here. usually, we disable sandbox during debug.
yami doesn't have knowledge of sandbox log system.