iio:accel:mma7455_core: Move exports into IIO_MMA7455 namespace

In order to avoid unnecessary pollution of the global symbol namespace
move the core mma7455 functions into an mma7455 specific namespace and
import that into the two bus modules.

For more information see https://lwn.net/Articles/760045/

Signed-off-by: Jonathan Cameron <[e-mail]>
Cc: Uwe Kleine-König <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

drivers/iio/accel/mma7455_core.c

···
 	.val_bits = 8,
 	.max_register = MMA7455_REG_TW,
 };
-EXPORT_SYMBOL_GPL(mma7455_core_regmap);
+EXPORT_SYMBOL_NS_GPL(mma7455_core_regmap, IIO_MMA7455);
 
 int mma7455_core_probe(struct device *dev, struct regmap *regmap,
 		       const char *name)
···
 
 	return 0;
 }
-EXPORT_SYMBOL_GPL(mma7455_core_probe);
+EXPORT_SYMBOL_NS_GPL(mma7455_core_probe, IIO_MMA7455);
 
 void mma7455_core_remove(struct device *dev)
 {
···
 	regmap_write(mma7455->regmap, MMA7455_REG_MCTL,
 		     MMA7455_MCTL_MODE_STANDBY);
 }
-EXPORT_SYMBOL_GPL(mma7455_core_remove);
+EXPORT_SYMBOL_NS_GPL(mma7455_core_remove, IIO_MMA7455);
 
 MODULE_AUTHOR("Joachim Eastwood <[e-mail]>");
 MODULE_DESCRIPTION("Freescale MMA7455L core accelerometer driver");

drivers/iio/accel/mma7455_i2c.c

···
 MODULE_AUTHOR("Joachim Eastwood <[e-mail]>");
 MODULE_DESCRIPTION("Freescale MMA7455L I2C accelerometer driver");
 MODULE_LICENSE("GPL v2");
+MODULE_IMPORT_NS(IIO_MMA7455);

drivers/iio/accel/mma7455_spi.c

···
 MODULE_AUTHOR("Joachim Eastwood <[e-mail]>");
 MODULE_DESCRIPTION("Freescale MMA7455L SPI accelerometer driver");
 MODULE_LICENSE("GPL v2");
+MODULE_IMPORT_NS(IIO_MMA7455);