[media] m88ds3103: use regmap for I2C register access

Use regmap for I2C register access.
Remove own I2C repeated mutex as it should not be needed. I2C adapter
lock is already taken when I2C mux adapter is called, no need for
double locking.
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/dvb-frontends/Kconfig

@@ -38,6 +38,7 @@ config DVB_STV6110x
 config DVB_M88DS3103
 	tristate "Montage Technology M88DS3103"
 	depends on DVB_CORE && I2C && I2C_MUX
+	select REGMAP_I2C
 	default m if !MEDIA_SUBDRV_AUTOSELECT
 	help
 	  Say Y when you want to support this frontend.

drivers/media/dvb-frontends/m88ds3103_priv.h

@@ -22,6 +22,7 @@
 #include "dvb_math.h"
 #include <linux/firmware.h>
 #include <linux/i2c-mux.h>
+#include <linux/regmap.h>
 #include <linux/math64.h>
 
 #define M88DS3103_FIRMWARE "dvb-demod-m88ds3103.fw"
@@ -32,8 +33,8 @@
 
 struct m88ds3103_dev {
 	struct i2c_client *client;
-	/* mutex needed due to own tuner I2C adapter */
-	struct mutex i2c_mutex;
+	struct regmap_config regmap_config;
+	struct regmap *regmap;
 	struct m88ds3103_config config;
 	const struct m88ds3103_config *cfg;
 	struct dvb_frontend fe;