mfd: axp20x: Probe axp20x_adc driver for AXP813

This makes the axp20x_adc driver probe with platform device id
"axp813-adc".
Signed-off-by: Quentin Schulz <quentin.schulz@bootlin.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/mfd/axp20x.c

@@ -885,7 +885,10 @@ static struct mfd_cell axp813_cells[] = {
 	}, {
 		.name			= "axp20x-gpio",
 		.of_compatible		= "x-powers,axp813-gpio",
-	}
+	}, {
+		.name			= "axp813-adc",
+		.of_compatible		= "x-powers,axp813-adc",
+	},
 };
 
 static struct axp20x_dev *axp20x_pm_power_off;