mfd: madera: 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 <[e-mail]>
Reviewed-by: Charles Keepax <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Lee Jones <[e-mail]>

include/linux/mfd/madera/pdata.h

···
 #ifndef MADERA_PDATA_H
 #define MADERA_PDATA_H
 
-#include <linux/kernel.h>
 #include <linux/regulator/arizona-ldo1.h>
 #include <linux/regulator/arizona-micsupp.h>
 #include <linux/regulator/machine.h>
+#include <linux/types.h>
+
 #include <sound/madera-pdata.h>
 
 #define MADERA_MAX_MICBIAS		4