mfd: wm831x: Don't forward declare enum wm831x_auxadc

We can't forward declare enums.

Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Samuel Ortiz <[e-mail]>

include/linux/mfd/wm831x/auxadc.h

···
 #ifndef __MFD_WM831X_AUXADC_H__
 #define __MFD_WM831X_AUXADC_H__
 
+struct wm831x;
+
 /*
  * R16429 (0x402D) - AuxADC Data
  */

include/linux/mfd/wm831x/core.h

···
 #include <linux/irqdomain.h>
 #include <linux/list.h>
 #include <linux/regmap.h>
+#include <linux/mfd/wm831x/auxadc.h>
 
 /*
  * Register values.
···
 };
 
 struct wm831x;
-enum wm831x_auxadc;
 
 typedef int (*wm831x_auxadc_read_fn)(struct wm831x *wm831x,
 				     enum wm831x_auxadc input);