x86/platform/intel/pmc_atom: Supply register mappings via PMC object

x86/platform/intel/pmc_atom: Supply register mappings via PMC object

The patch converts the functions to use the register mappings
provided by PMC object. It would help in case of mappings on
different platforms.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Aubrey Li <aubrey.li@linux.intel.com>
Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com>
Cc: Kumar P Mahesh <mahesh.kumar.p@intel.com>
Link: http://lkml.kernel.org/r/1436192944-56496-4-git-send-email-andriy.shevchenko@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>