mfd: max77693: Map charger device to its own of_node

Add a "maxim,max77693-charger" of_compatible to the mfd_cell so the MFD
child device (the charger) will have its own of_node set. This will be
used by the max77693 charger driver in next patches to obtain battery
configuration from DTS.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/mfd/max77693.c

@@ -43,7 +43,10 @@
 
 static const struct mfd_cell max77693_devs[] = {
 	{ .name = "max77693-pmic", },
-	{ .name = "max77693-charger", },
+	{
+		.name = "max77693-charger",
+		.of_compatible = "maxim,max77693-charger",
+	},
 	{ .name = "max77693-muic", },
 	{
 		.name = "max77693-haptic",