mfd: cs42l43: Tidy up header includes

Use more forward declarations, move header guards to cover other
includes, and rely less on including headers through other headers.
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20240129152557.3221212-2-ckeepax@opensource.cirrus.comSigned-off-by: Lee Jones <lee@kernel.org>

drivers/mfd/cs42l43-i2c.c

@@ -6,11 +6,15 @@
  *                         Cirrus Logic International Semiconductor Ltd.
  */
 
+#include <linux/array_size.h>
 #include <linux/err.h>
-#include <linux/errno.h>
 #include <linux/i2c.h>
+#include <linux/mfd/cs42l43.h>
 #include <linux/mfd/cs42l43-regs.h>
+#include <linux/mod_devicetable.h>
 #include <linux/module.h>
+#include <linux/pm.h>
+#include <linux/regmap.h>
 
 #include "cs42l43.h"
 

drivers/mfd/cs42l43-sdw.c

@@ -6,11 +6,15 @@
  *                         Cirrus Logic International Semiconductor Ltd.
  */
 
+#include <linux/array_size.h>
 #include <linux/device.h>
 #include <linux/err.h>
-#include <linux/errno.h>
+#include <linux/mfd/cs42l43.h>
 #include <linux/mfd/cs42l43-regs.h>
+#include <linux/mod_devicetable.h>
 #include <linux/module.h>
+#include <linux/pm.h>
+#include <linux/regmap.h>
 #include <linux/soundwire/sdw.h>
 #include <linux/soundwire/sdw_registers.h>
 #include <linux/soundwire/sdw_type.h>

drivers/mfd/cs42l43.c

@@ -6,18 +6,24 @@
  *                         Cirrus Logic International Semiconductor Ltd.
  */
 
+#include <linux/array_size.h>
 #include <linux/bitops.h>
 #include <linux/build_bug.h>
 #include <linux/delay.h>
+#include <linux/device.h>
 #include <linux/err.h>
-#include <linux/errno.h>
 #include <linux/firmware.h>
+#include <linux/gpio/consumer.h>
 #include <linux/jiffies.h>
 #include <linux/mfd/core.h>
+#include <linux/mfd/cs42l43.h>
 #include <linux/mfd/cs42l43-regs.h>
 #include <linux/module.h>
+#include <linux/pm.h>
 #include <linux/pm_runtime.h>
+#include <linux/regmap.h>
 #include <linux/soundwire/sdw.h>
+#include <linux/types.h>
 
 #include "cs42l43.h"
 

drivers/mfd/cs42l43.h

@@ -6,15 +6,17 @@
  *                         Cirrus Logic International Semiconductor Ltd.
  */
 
-#include <linux/mfd/cs42l43.h>
-#include <linux/pm.h>
-#include <linux/regmap.h>
-
 #ifndef CS42L43_CORE_INT_H
 #define CS42L43_CORE_INT_H
 
 #define CS42L43_N_DEFAULTS 176
 
+struct dev_pm_ops;
+struct device;
+struct reg_default;
+
+struct cs42l43;
+
 extern const struct dev_pm_ops cs42l43_pm_ops;
 extern const struct reg_default cs42l43_reg_default[CS42L43_N_DEFAULTS];
 

include/linux/mfd/cs42l43.h

@@ -6,20 +6,21 @@
  *                         Cirrus Logic International Semiconductor Ltd.
  */
 
+#ifndef CS42L43_CORE_EXT_H
+#define CS42L43_CORE_EXT_H
+
 #include <linux/completion.h>
-#include <linux/device.h>
-#include <linux/gpio/consumer.h>
 #include <linux/mutex.h>
 #include <linux/regmap.h>
 #include <linux/regulator/consumer.h>
-#include <linux/soundwire/sdw.h>
 #include <linux/workqueue.h>
 
-#ifndef CS42L43_CORE_EXT_H
-#define CS42L43_CORE_EXT_H
-
 #define CS42L43_N_SUPPLIES		3
 
+struct device;
+struct gpio_desc;
+struct sdw_slave;
+
 enum cs42l43_irq_numbers {
 	CS42L43_PLL_LOST_LOCK,
 	CS42L43_PLL_READY,