gpiolib: Add WM8994 GPIO support

The WM8994 has 11 GPIO lines.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 90b0880..594bb70 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -26,3 +26,4 @@
 obj-$(CONFIG_GPIO_VR41XX)	+= vr41xx_giu.o
 obj-$(CONFIG_GPIO_WM831X)	+= wm831x-gpio.o
 obj-$(CONFIG_GPIO_WM8350)	+= wm8350-gpiolib.o
+obj-$(CONFIG_GPIO_WM8994)	+= wm8994-gpio.o