iio:st-sensors: Remove duplicate MODULE_*

The core module and type specific core modules are made up of
several files. There is no benefit in duplicating the MODULE_* macros
in each file so remove them.

Noticed whilst adding MODULE_IMPORT_NS() as I missed some files and
it still worked, making it clear not all of these blocks were needed.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Denis Ciocca <denis.ciocca@st.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20220116180535.2367780-13-jic23@kernel.org