[PATCH v2] gpio: add Intel Moorestown Platform Langwell chip gpiodriver

[Alek Du]

Changes from v1:
1. driver name changed from lnw.c ==> langwell_gpio.c
2. removed hard coded driver data, now we get it from PCI bar1 (platform init code fills it)
3. removed alternative function setting code, it should be called in platform init part.
4. misc. style clean