dmaengine: idxd: add pid to exported sysfs attribute for opened file

dmaengine: idxd: add pid to exported sysfs attribute for opened file

Provide the pid of the application for the opened file. This allows the
monitor daemon to easily correlate which app opened the file and easily
kill the app by pid if that is desired action.

Tested-by: Tony Zhu <tony.zhu@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: https://lore.kernel.org/r/20230407203143.2189681-16-fenghua.yu@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>