mfd: Move pcf50633 irq related functions to its own file.

This reduces code clutter a bit and will ease an migration to genirq.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 8593496..ca1517e 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -57,7 +57,8 @@
 max8925-objs			:= max8925-core.o max8925-i2c.o
 obj-$(CONFIG_MFD_MAX8925)	+= max8925.o
 
-obj-$(CONFIG_MFD_PCF50633)	+= pcf50633-core.o pcf50633-irq.o
+pcf50633-objs			:= pcf50633-core.o pcf50633-irq.o
+obj-$(CONFIG_MFD_PCF50633)	+= pcf50633.o
 obj-$(CONFIG_PCF50633_ADC)	+= pcf50633-adc.o
 obj-$(CONFIG_PCF50633_GPIO)	+= pcf50633-gpio.o
 obj-$(CONFIG_ABX500_CORE)	+= abx500-core.o