mfd: wm8350-core: Don't use "proxy" headers

Update header inclusions to follow IWYU (Include What You Use)
principle.

Note that kernel.h is discouraged to be included as it's written
at the top of that file.

Signed-off-by: Andy Shevchenko <[email protected]>
Reviewed-by: Charles Keepax <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Lee Jones <[email protected]>

Author: andy-shev

include/linux/mfd/wm8350/core.h

@@ -8,11 +8,12 @@
 #ifndef __LINUX_MFD_WM8350_CORE_H_
 #define __LINUX_MFD_WM8350_CORE_H_
 
-#include <linux/kernel.h>
-#include <linux/mutex.h>
-#include <linux/interrupt.h>
 #include <linux/completion.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/mutex.h>
 #include <linux/regmap.h>
+#include <linux/types.h>
 
 #include <linux/mfd/wm8350/audio.h>
 #include <linux/mfd/wm8350/gpio.h>
@@ -21,6 +22,9 @@
 #include <linux/mfd/wm8350/supply.h>
 #include <linux/mfd/wm8350/wdt.h>
 
+struct device;
+struct platform_device;
+
 /*
  * Register values.
  */