Add support for gpio on Intel BayTrail platforms. BayTrail supports 3 banks
of gpios called SCORE, NCORE ans SUS with 102, 28 and 44 gpio pins.
Supports gpio interrupts and ACPI gpio events

Pins may be muxed to alternate function instead of gpio by firmware.
This driver does not touch the pin muxing and expect firmare
to set pin muxing and pullup/down properties properly.
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>