x86/intel_rdt: Introduce pseudo-locked region

A pseudo-locked region is introduced representing an instance of a
pseudo-locked cache region. Each cache instance (domain) can support one
pseudo-locked region. Similarly a resource group can be used for one
pseudo-locked region.

Include a pointer to a pseudo-locked region from the domain and resource
group structures.

Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: fenghua.yu@intel.com
Cc: tony.luck@intel.com
Cc: vikas.shivappa@linux.intel.com
Cc: gavin.hindman@intel.com
Cc: jithu.joseph@intel.com
Cc: dave.hansen@intel.com
Cc: hpa@zytor.com
Link: https://lkml.kernel.org/r/9f69eb159051067703bcbc714de62e69874d5dee.1529706536.git.reinette.chatre@intel.com