iio: fix pressure data output unit in hid-sensor-attributes

iio: fix pressure data output unit in hid-sensor-attributes

According to IIO ABI definition, IIO_PRESSURE data output unit is
kilopascal:
http://lxr.free-electrons.com/source/Documentation/ABI/testing/sysfs-bus-iio

This patch fix output unit of HID pressure sensor IIO driver from pascal to
kilopascal to follow IIO ABI definition.

Signed-off-by: Kweh, Hock Leong <hock.leong.kweh@intel.com>
Reviewed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>