iio: isl29028: add isl29030 support

isl29030 is basically the same chip. The only difference
is the chip's first pin. For isl29028 its named ADDR0 and
can be used to change the chip's i2c address. For isl29030
on the other hand that pin is named Ials and is an analog
current output proportional to ALS/IR. This change is
irrelevant for the Linux driver.

This has been tested on Motorola Droid 4.

Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>