gpio: max732x: convert to GPIOLIB_IRQCHIP

Take a sweep to bring the irq support for the MAX732x expanders
into the gpiolib core to cut down on duplicated code.

Only compile tested! I need some feedback from people using this
expander with interrupts to tell me if things go right or
wrong when I do this.

Cc: Semen Protsenko <semen.protsenko@globallogic.com>
Cc: Mans Rullgard <mans@mansr.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index c1e2ca3..09bc70b 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -543,7 +543,6 @@
 config GPIO_MAX732X
 	tristate "MAX7319, MAX7320-7327 I2C Port Expanders"
 	depends on I2C
-	select IRQ_DOMAIN
 	help
 	  Say yes here to support the MAX7319, MAX7320-7327 series of I2C
 	  Port Expanders. Each IO port on these chips has a fixed role of
@@ -563,6 +562,7 @@
 config GPIO_MAX732X_IRQ
 	bool "Interrupt controller support for MAX732x"
 	depends on GPIO_MAX732X=y
+	select GPIOLIB_IRQCHIP
 	help
 	  Say yes here to enable the max732x to be used as an interrupt
 	  controller. It requires the driver to be built in the kernel.