staging:iio:imu:adis16350 etc support into adis16400 driver.

Next patch will remove the current adis16350 driver.
These should have been merged a long time ago, but there we are.

V3: rebase fixup + add missing extend_name for supply on adis16350

V2: Move to single IIO_CHAN macro + use the new extend_name
to make the naming of the temperature sensors contain x, y, z
rather than messing with modifiers.  This a very weird case
and I don't want temperature to use axial modifiers.

Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>