This patch adds device-tree support to the SMB347 charger driver. All
legacy platform data now can be parsed from DT. Because of that and since
SMB347 is an I2C client driver, the IRQ number can be passed automatically
through client's IRQ variable if it's defined in DT. There is no need to
map GPIO to IRQ manually in the case of DT.

This patch is based on the original work made by:
Jonghwa Lee <jonghwa3.lee@samsung.com>
Link: https://patchwork.kernel.org/patch/4284731/Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: David Heidelberg <david@ixit.cz>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>