hwmon: Move the IIO client driver for hwmon out of staging

This driver uses channel maps, defined either through device tree
or platform data, to create a hwmon driver which acts as a client
for the underlying IIO device channels.  Thus a general purpose
IIO adc driver can be used to provide hardware monitoring using a subset
of its channels.

Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Acked-by: Guenter Roeck <linux@roeck-us.net>

--
 The only non move changes here concern the description and changes to the
 dependencies to IIO explicit and hwmon implicit.

 I'm proposing moving this into hwmon on the basis of placing drivers
 based on what they provide rather than what their underlying hardware
 is.

 drivers/hwmon/Kconfig           |   9 ++
 drivers/hwmon/Makefile          |   1 +
 drivers/hwmon/iio_hwmon.c       | 196 ++++++++++++++++++++++++++++++++++++++++
 drivers/staging/iio/Kconfig     |   8 --
 drivers/staging/iio/Makefile    |   2 -
 drivers/staging/iio/iio_hwmon.c | 196 ----------------------------------------
 6 files changed, 206 insertions(+), 206 deletions(-)