iio: types: Added support for rotation from north usage attributes

Added the rotation from north usage attributes to the iio modifier enum and to the iio modifier names array.

Signed-off-by: Reyad Attiyat <reyad.attiyat@gmail.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>