qpnp-fg-gen3: update the FCC unit while notifying charger

Charger driver expects the constant_charge_current_max property
in microunits. Update it.

Change-Id: I1b9117edb6c2206c09deb083529479a3ccc4618d
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>