iio: proximity: vcnl3020: remove iio_claim/release_direct

Remove iio_claim/release and change it on mutex accordingly in
vcnl3020_write_proxy_samp_freq.

Signed-off-by: Ivan Mikhaylov <i.mikhaylov@yadro.com>
Link: https://lore.kernel.org/r/20210722154420.915082-4-i.mikhaylov@yadro.com


Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>