power: supply: bq27xxx: fix polarity of current_now

stable inclusion
from stable-v5.10.182
commit 14e1a958d9884e15101b42cbdde8e644a04ed7a3
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8GJZJ

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=14e1a958d9884e15101b42cbdde8e644a04ed7a3



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[ Upstream commit cd060b4d ]

current_now has to be negative during discharging and positive during
charging, the behavior seen is the other way round.

Tested on GTA04 with Openmoko battery.

Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Stable-dep-of: 35092c58 ("power: supply: bq27xxx: Add cache parameter to bq27xxx_battery_current_and_status()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>