mfd: Add pm8xxx irq support

Add support for the irq controller in Qualcomm 8xxx pmic. The 8xxx
interrupt controller provides control for gpio and mpp configured as
interrupts in addition to other subdevice interrupts. The interrupt
controller also provides a way to read the real time status of an
interrupt. This real time status is the only way one can get the
input values of gpio and mpp lines.

Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index d423288..8344fc0 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -709,6 +709,16 @@
 	  Say M here if you want to include support for PM8921 chip as a module.
 	  This will build a module called "pm8921-core".
 
+config MFD_PM8XXX_IRQ
+	bool "Support for Qualcomm PM8xxx IRQ features"
+	depends on MFD_PM8XXX
+	default y if MFD_PM8XXX
+	help
+	  This is the IRQ driver for Qualcomm PM 8xxx PMIC chips.
+
+	  This is required to use certain other PM 8xxx features, such as GPIO
+	  and MPP.
+
 endif # MFD_SUPPORT
 
 menu "Multimedia Capabilities Port drivers"