x86/intel_rdt: Make useful functions available internally

In support of the work done to enable resource groups to have different
modes some static functions need to be available for sharing amongst
all RDT components.

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/2af8fd6e937ae4fbdaa52dee1123823cb4993176.1529706536.git.reinette.chatre@intel.com