x86/intel_rdt: Organize code properly

Having init functions at random places in the middle of the code is
unintuitive.

Move them close to the init routine and mark them __init.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: ravi.v.shankar@intel.com
Cc: tony.luck@intel.com
Cc: fenghua.yu@intel.com
Cc: vikas.shivappa@intel.com