max17042: Add support for signalling change in SOC

If platform has the alert pin attached to an interrupt source have the
driver signal a change in the SOC every 1 percent.

Signed-off-by: Ramakrishna Pallala <ramakrishna.pallala@intel.com>
Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>