Third set of new functionality and cleanups for IIO in the 3.13 cycle. Driver New Functionality * MXS - new interrupt driven touch screen support for i.MX23/28. Old polled implementation dropped. Driver Cleanups * Some spi_sync boilerplate dropped by using spi_sync_transfer * Some switching of drivers to the fractional type for scale reading. Moves the ugly calculation into one place. * Fix the documentation for *_voltage_scale which is never been correct or as implemented in any driver. * HID sensor hub and children : Open the sensor hub only when someone cares. * hmc5843 - various minor