iio: hid-sensor-prox: Split difference from multiple channels

When the driver was originally created, it was decided that
sampling_frequency and hysteresis would be shared_per_type instead
of shared_by_all (even though it is internally shared by all). Eg:
in_proximity_raw
in_proximity_sampling_frequency

When we introduced support for more channels, we continued with
shared_by_type which. Eg:
in_proximity0_raw
in_proximity1_raw
in_proximity_sampling_frequency
in_attention_raw
in_attention_sampling_frequency

Ideally we should change to shared_by_all, but it is not an option,
because the current naming has been a stablished ABI by now. Luckily we
can use separate instead. That will be more consistent:
in_proximity0_raw
in_proximity0_sampling_frequency
in_proximity1_raw
in_proximity1_sampling_frequency
in_attention_raw
in_attention_sampling_frequency

Fixes: 596ef5cf ("iio: hid-sensor-prox: Add support for more channels")
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Link: https://patch.msgid.link/20241216-fix-hid-sensor-v2-1-ff8c1959ec4a@chromium.org


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