[media] mn88473: convert to RegMap API

Convert driver to I2C RegMap API. That offers unified register
access routines, register value caching and more.

We need 3 register maps, one for each register page, as chips has
3 I2C address.
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/dvb-frontends/Kconfig

@@ -474,6 +474,7 @@ config DVB_SI2168
 config DVB_MN88473
 	tristate "Panasonic MN88473"
 	depends on DVB_CORE && I2C
+	select REGMAP_I2C
 	default m if !MEDIA_SUBDRV_AUTOSELECT
 	help
 	  Say Y when you want to support this frontend.

drivers/media/dvb-frontends/mn88473_priv.h

@@ -20,11 +20,13 @@
 #include "dvb_frontend.h"
 #include "mn88473.h"
 #include <linux/firmware.h>
+#include <linux/regmap.h>
 
 #define MN88473_FIRMWARE "dvb-demod-mn88473-01.fw"
 
 struct mn88473_dev {
 	struct i2c_client *client[3];
+	struct regmap *regmap[3];
 	struct dvb_frontend fe;
 	u16 i2c_wr_max;
 	fe_delivery_system_t delivery_system;