power: fg-gen4/qg: initialize locale variable before use

The power supply framework de-references the power_supply_cfg
structure members. Initialize them to NULL to avoid invalid access.

Change-Id: If4d18c623c12ed5b8d52c66d471f2f6f07a70813
Signed-off-by: Ashay Jaiswal <ashayj@codeaurora.org>