mfd: max14577: Select REGMAP_IRQ

MAXIM 14577 MFD driver uses the regmap_irq_chip so it's Kconfig entry
should select REGMAP_IRQ.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 7838a5d..d22ca0f 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -327,6 +327,7 @@
 	depends on I2C=y
 	select MFD_CORE
 	select REGMAP_I2C
+	select REGMAP_IRQ
 	select IRQ_DOMAIN
 	help
 	  Say yes here to add support for Maxim Semiconductor MAX14577.