qpnp-fg-gen3: add support to restart fuel gauge

Add a module parameter "fg_restart" to restart the fuel gauge
without loading the battery profile. This will be useful in
geting a fresh SOC estimate whenever required.

Change-Id: I0c054ad523a0eab72f777d010807bb3a55f63f7e
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>