power: qpnp-qg: Fix assignment of recharge_soc

Recharge-soc may get assigned to a random value if
the property is missing. Fix this.

Change-Id: I862545b7f4930bb42e37ec36d0558eb8a5c3cefd
Signed-off-by: Anirudh Ghayal <aghayal@codeaurora.org>