power: qpnp-smbcharger: qpnp-fg: support soc based charging resume

Add a property qcom,resume-soc-threshold. If this property is set, the
charger will automatically restart charging whenever the fuelgauge
reports an SOC below that value.

CRs-Fixed: 709566
Change-Id: Ie78162245fa429b569ebf3b00b8f83ad31cda0f6
Signed-off-by: Xiaozhe Shi <xiaozhes@codeaurora.org>