iio: hid-sensors: Add hinge sensor driver

The Hinge sensor is a common custom sensor on laptops. It calculates
the angle between the lid (screen) and the base (keyboard). In addition,
it also exposes screen and the keyboard angles with respect to the
ground. Applications can easily get laptop's status in space through
this sensor, in order to display appropriate user interface.

Signed-off-by: Ye Xiang <xiang.ye@intel.com>
Link: https://lore.kernel.org/r/20201215054444.9324-3-xiang.ye@intel.com


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