mfd: Add LPC driver for Intel ICH chipsets

This driver currently creates resources for use by a forthcoming ICH
chipset GPIO driver. It could be expanded to create the resources for
converting the esb2rom (mtd) and iTCO_wdt (wdt), and potentially more,
drivers to use the mfd model.

Signed-off-by: Aaron Sierra <asierra@xes-inc.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>