mfd: Remove unused io_lock mutex from da9052

da9052 has been converted to use regmap API, so we can remove the unused
io_lock mutex.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/mfd/da9052-core.c

@@ -16,7 +16,6 @@
 #include <linux/input.h>
 #include <linux/interrupt.h>
 #include <linux/irq.h>
-#include <linux/mutex.h>
 #include <linux/mfd/core.h>
 #include <linux/slab.h>
 #include <linux/module.h>
@@ -647,8 +646,6 @@ int __devinit da9052_device_init(struct da9052 *da9052, u8 chip_id)
 	struct irq_desc *desc;
 	int ret;
 
-	mutex_init(&da9052->io_lock);
-
 	if (pdata && pdata->init != NULL)
 		pdata->init(da9052);
 

include/linux/mfd/da9052/da9052.h

@@ -76,8 +76,6 @@ enum da9052_chip_id {
 struct da9052_pdata;
 
 struct da9052 {
-	struct mutex io_lock;
-
 	struct device *dev;
 	struct regmap *regmap;