iio: humidity: hdc2010: Drop duplicate setting of iio_dev.dev.parent

Already set to same value in devm_iio_device_alloc()

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Eugene Zaikonnikov <ez@norphonic.com>
Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Link: https://lore.kernel.org/r/20210426170251.351957-7-jic23@kernel.org