abb_fg: Updates from cocore kernel

Squashed commits from cocafe:
abb-fg: Hacky poweroff threshold
By default, poweroff threshold is 3300mV, now we make it 3000mV.

Signed-off-by: cocafe <cocafehj@gmail.com>

abb-fg: Code style

abb-fg: Adjust poweroff threshold 3000mV -> 3100mV
When battery is too low,
it might be unable to supply some stuff like
sdcard slot which require maximum voltage 2.8V.

Signed-off-by: cocafe <cocafehj@gmail.com>

abb-fg: Allow to report battery capacity goes up
Signed-off-by: cocafe <cocafehj@gmail.com>

abb-fg: Disable BATTOK register
Because of BATTOK dectection, when battery is low,
AB8500 will shut down instead of using software method,
which may lose user data. Disable it.

Signed-off-by: cocafe <cocafehj@gmail.com>