power: qpnp-fg: add module parameter to restart the fuel gauge hardware

Add the module parameter "restart" to the fuel gauge driver. Writing
into this parameter will issue a restart command to the fuel gauge,
restarting the fuel gauge internal SOC variables.

While the restart is progressing, the module parameter will read 1.
Otherwise it will read 0.

CRs-Fixed: 819622
Change-Id: I92a84491900affae85427eae2351da810a6eea27
Signed-off-by: Xiaozhe Shi <xiaozhes@codeaurora.org>