mfd: axp20x: Add AXP209 GPIO support

Now that we have a GPIO driver for the AXP209, we can add it to our MFD.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
diff --git a/drivers/mfd/axp20x.c b/drivers/mfd/axp20x.c
index 9610275..ba130be 100644
--- a/drivers/mfd/axp20x.c
+++ b/drivers/mfd/axp20x.c
@@ -566,6 +566,9 @@
 
 static struct mfd_cell axp20x_cells[] = {
 	{
+		.name		= "axp20x-gpio",
+		.of_compatible	= "x-powers,axp209-gpio",
+	}, {
 		.name		= "axp20x-pek",
 		.num_resources	= ARRAY_SIZE(axp20x_pek_resources),
 		.resources	= axp20x_pek_resources,