add the support of multiple context tracing

add the support of multiple context tracing

Libva has a limited tracing function before. If more than one context is created
in one instance, then this tracing can't work and output wrong log messages.
This patch fixes this problem. Tracing is possible while multiple contexts are
being used.

Each log file name is suffixed by thread id. This file has all log message from
this thread. Each surface or codedbuf dump file name is suffixed by context id.
This file has all surface or codedbuf data of this context.

Signed-off-by: peng.chen <peng.c.chen@intel.com>
Reviewed-by: Sean V Kelley <sean.v.kelley@intel.com>
Tested-by: Daniel Charles <daniel.charles@intel.com>