iio: adc: hx711: remove hx711_remove()

iio: adc: hx711: remove hx711_remove()

By using a few more devm_ functions, we can remove the hx711_remove()
function in the hx711 driver.

platform_set_drvdata() is also removed since there are no more
callers of platform_get_drvdata().

Signed-off-by: David Lechner <dlechner@baylibre.com>
Reviewed-by: Andreas Klinger <ak@it-klinger.de>
Link: https://patch.msgid.link/20240621-iio-regulator-refactor-round-2-v1-3-49e50cd0b99a@baylibre.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>