qpnp-fg-gen3: Limit how frequently fg data can be queried

Querying the fuelgauge for data is expensive, so doing it frequently can
result in a significant increase in power consumption. The fuelgauge
also only generates fresh statistics once per second.

Limit how frequently data queries can be sent to 2 seconds in order to
prevent fuelgauge queries from consuming too much power. Only do this
while there is no USB cable connected to the device, since the charging
drivers need fresh statistics when there's a USB cable connected.

[mcdachappe: Limit data queries to 5 seconds]