iio: light: vcnl4000: Add interrupt support for vcnl4040

Add support to configure proximity sensor interrupts and threshold
limits for vcnl4040. If an interrupt is detected an event will be
pushed to the event interface.

Signed-off-by: Mårten Lindahl <marten.lindahl@axis.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230117190017.3789181-4-marten.lindahl@axis.com


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