mfd: twl-core: Register twl4030-madc child only for twl4030 class

twl4030-madc driver can only handle twl4030 class MADC. The newer revisions
of twl does not have MADC, instead they have different IP called GPADC which
is not backward compatible.
Acked-by: NTero Kristo <t-kristo@ti.com>
Signed-off-by: NPeter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

drivers/mfd/twl-core.c

@@ -646,7 +646,8 @@ add_children(struct twl4030_platform_data *pdata, unsigned irq_base,
 			return PTR_ERR(child);
 	}
 
-	if (IS_ENABLED(CONFIG_TWL4030_MADC) && pdata->madc) {
+	if (IS_ENABLED(CONFIG_TWL4030_MADC) && pdata->madc &&
+	    twl_class_is_4030()) {
 		child = add_child(2, "twl4030_madc",
 				pdata->madc, sizeof(*pdata->madc),
 				true, irq_base + MADC_INTR_OFFSET, 0);