mfd: wm8994: Export symbols ready for built-in => modular build

We'd like to be able to build the WM8994 family as modules, but the
build will fail if the external symbols aren't exported first.

Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
diff --git a/drivers/mfd/wm8994-irq.c b/drivers/mfd/wm8994-irq.c
index e74dedd..a14407e 100644
--- a/drivers/mfd/wm8994-irq.c
+++ b/drivers/mfd/wm8994-irq.c
@@ -262,8 +262,10 @@
 
 	return 0;
 }
+EXPORT_SYMBOL(wm8994_irq_init);
 
 void wm8994_irq_exit(struct wm8994 *wm8994)
 {
 	regmap_del_irq_chip(wm8994->irq, wm8994->irq_data);
 }
+EXPORT_SYMBOL(wm8994_irq_exit);