x86/intel/lpss: Add pin control support to Intel low power subsystem

x86/intel/lpss: Add pin control support to Intel low power subsystem

x86 chips with LPSS (low power subsystem) such as Lynxpoint and
Baytrail have SoC like peripheral support and controllable pins.

At the moment, Baytrail needs the pinctrl-baytrail driver to let
peripherals control their gpio resources, but more pincontrol
functions such as pin muxing and grouping are possible to add
later.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: http://lkml.kernel.org/r/1379080949-21734-1-git-send-email-mathias.nyman@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>