mfd: da9052: Introduce da9052-irq.c

Create a da9052-irq.c file so that it can handle interrupt related functions.

This is useful for allowing the da9052 drivers to use such functions
when dealing with da9052 interrupts.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index a30c49e..632cce0 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -90,6 +90,7 @@
 
 obj-$(CONFIG_PMIC_DA903X)	+= da903x.o
 
+obj-$(CONFIG_PMIC_DA9052)	+= da9052-irq.o
 obj-$(CONFIG_PMIC_DA9052)	+= da9052-core.o
 obj-$(CONFIG_MFD_DA9052_SPI)	+= da9052-spi.o
 obj-$(CONFIG_MFD_DA9052_I2C)	+= da9052-i2c.o