leds: leds-pca955x: Use dev_info instead of printk

Fixes the following checkpatch warning:
WARNING: Prefer netdev_info(netdev, ... then dev_info(dev, ...
then pr_info(...  to printk(KERN_INFO ...

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Bryan Wu <cooloney@gmail.com>