This patch adds API's to read/write/update PMC GC registers.
PMC dependent devices like iTCO_wdt, Telemetry has requirement
to acces GCR registers. These API's can be used for this
purpose.
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>