x86/resctrl: Fix kernel-doc in internal.h

Add description of undocumented parameters. Issues detected by
scripts/kernel-doc.

Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lkml.kernel.org/r/20210618223206.29539-1-fmdefrancesco@gmail.com