gpio / ACPI: add ACPI support

Add support for translating ACPI GPIO pin numbers to Linux GPIO API pins.
Needs a gpio controller driver with the acpi handler hook set.

Drivers can use acpi_get_gpio() to translate ACPI5 GpioIO and GpioInt
resources to Linux GPIO's.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 9aeed67..420dbac 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -4,6 +4,7 @@
 
 obj-$(CONFIG_GPIOLIB)		+= gpiolib.o devres.o
 obj-$(CONFIG_OF_GPIO)		+= gpiolib-of.o
+obj-$(CONFIG_GPIO_ACPI)		+= gpiolib-acpi.o
 
 # Device drivers. Generally keep list sorted alphabetically
 obj-$(CONFIG_GPIO_GENERIC)	+= gpio-generic.o