hwmon: (ina2xx) drop unused platform data

hwmon: (ina2xx) drop unused platform data

Nobody defines struct ina2xx_platform_data. Remove platform data support
from the drivers which still have it (it's effectively dead code) and
remove the header.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Acked-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Link: https://lore.kernel.org/r/20260326-drop-ina2xx-pdata-v1-1-c159437bb2df@oss.qualcomm.com
[groeck: Fixed continuation line alignment]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>