iio:temperature: Add support for TI TMP007 sensor

This patch adds support for TI TMP007 - 16 bit IR thermopile sensor with integrated Math engine.
Sensor takes care of calculating the object temperature with the help of calibrated constants stored in non-volatile memory,
thereby reducing the calculation overhead.

Signed-off-by: Manivannan Sadhasivam <manivannanece23@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>