gpio: Add support for Intel ICHx/3100/Series[56] GPIO

gpio: Add support for Intel ICHx/3100/Series[56] GPIO

This driver works on many Intel chipsets, including the ICH6, ICH7,
ICH8, ICH9, ICH10, 3100, Series 5/3400 (Ibex Peak), Series 6/C200
(Cougar Point), and NM10 (Tiger Point).

Additional Intel chipsets should be easily supported if needed, eg the
ICH1-5, EP80579, etc.

Tested on QM67 (Cougar Point), QM57 (Ibex Peak), 3100 (Whitmore Lake),
and NM10 (Tiger Point).

Includes work from Jean Delvare:
        - Resource leak removal during module load/unload
        - GPIO API bit value enforcement

Also includes code cleanup from Guenter Roeck and Grant Likely.

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
Signed-off-by: Aaron Sierra <asierra@xes-inc.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>