mfd: Convert 88pm860x to use regmap api

Convert the 88pm860x normal bank register read/write to
use the register map API.

Signed-off-by: Jett.Zhou <jtzhou@marvell.com>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/include/linux/mfd/88pm860x.h b/include/linux/mfd/88pm860x.h
index 63b4fb8..92be347 100644
--- a/include/linux/mfd/88pm860x.h
+++ b/include/linux/mfd/88pm860x.h
@@ -297,10 +297,11 @@
 
 struct pm860x_chip {
 	struct device		*dev;
-	struct mutex		io_lock;
 	struct mutex		irq_lock;
 	struct i2c_client	*client;
 	struct i2c_client	*companion;	/* companion chip client */
+	struct regmap           *regmap;
+	struct regmap           *regmap_companion;
 
 	int			buck3_double;	/* DVC ramp slope double */
 	unsigned short		companion_addr;