iio: pressure: bmp280: Move symbol exports to IIO_BMP280 namespace

Avoid unnecessary pollution of the global symbol namespace by
moving library functions in to a specific namespace and import
that into the drivers that make use of the functions.

For more info: https://lwn.net/Articles/760045/

Signed-off-by: Jonathan Cameron <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Reviewed-By: Joe Simmons-Talbott <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jonathan Cameron <[e-mail]>

drivers/iio/pressure/bmp280-core.c

···
 
 	return devm_iio_device_register(dev, indio_dev);
 }
-EXPORT_SYMBOL(bmp280_common_probe);
+EXPORT_SYMBOL_NS(bmp280_common_probe, IIO_BMP280);
 
 static int bmp280_runtime_suspend(struct device *dev)
 {

drivers/iio/pressure/bmp280-i2c.c

···
 MODULE_AUTHOR("Vlad Dogaru <[e-mail]>");
 MODULE_DESCRIPTION("Driver for Bosch Sensortec BMP180/BMP280 pressure and temperature sensor");
 MODULE_LICENSE("GPL v2");
+MODULE_IMPORT_NS(IIO_BMP280);

drivers/iio/pressure/bmp280-regmap.c

···
 	.writeable_reg = bmp180_is_writeable_reg,
 	.volatile_reg = bmp180_is_volatile_reg,
 };
-EXPORT_SYMBOL(bmp180_regmap_config);
+EXPORT_SYMBOL_NS(bmp180_regmap_config, IIO_BMP280);
 
 static bool bmp280_is_writeable_reg(struct device *dev, unsigned int reg)
 {
···
 	.writeable_reg = bmp280_is_writeable_reg,
 	.volatile_reg = bmp280_is_volatile_reg,
 };
-EXPORT_SYMBOL(bmp280_regmap_config);
+EXPORT_SYMBOL_NS(bmp280_regmap_config, IIO_BMP280);

drivers/iio/pressure/bmp280-spi.c

···
 
 MODULE_DESCRIPTION("BMP280 SPI bus driver");
 MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(IIO_BMP280);