mfd: Use generic irq chip for jz4740-adc

Use the generic irq chip framework for implementing the irq chip for
the jz4740-adc driver.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 37b83eb..1e2c9f03 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -662,8 +662,9 @@
 	  CAN and GPIO controllers.
 
 config MFD_JZ4740_ADC
-	tristate "Support for the JZ4740 SoC ADC core"
+	bool "Support for the JZ4740 SoC ADC core"
 	select MFD_CORE
+	select GENERIC_IRQ_CHIP
 	depends on MACH_JZ4740
 	help
 	  Say yes here if you want support for the ADC unit in the JZ4740 SoC.