iio: Add ABI documentation for proximity

has been in use for a long time, but never documented
proximity is unit-less, except otherwise stated, see e.g.
the as3935 driver where it is meter

Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This commit is contained in:
Peter Meerwald 2014-03-05 11:57:00 +00:00 • committed by Jonathan Cameron
commit 6c0690ecb6