88pm860x_battery and charger: Fix a few post-merge issues

Sparse complains:

  CHECK   drivers/power/88pm860x_battery.c
drivers/power/88pm860x_battery.c:128:5: warning: symbol 'array_soc' was not declared. Should it be static?
  CHECK   drivers/power/88pm860x_charger.c
drivers/power/88pm860x_charger.c:640:3: warning: symbol 'pm860x_irq_descs' was not declared. Should it be static?
  CHECK   drivers/mfd/88pm860x-core.c
drivers/mfd/88pm860x-core.c:803:53: warning: incorrect type in assignment (different base types)
drivers/mfd/88pm860x-core.c:803:53:    expected struct charger_regulator *charger_regulators
drivers/mfd/88pm860x-core.c:803:53:    got struct regulator_bulk_data static [toplevel] *

The issues are minor, except for the last one. We seemed to use
'regulator_bulk_data' struct (just as charger manager documentation
wrongly tells us), but in real it should have been
'struct charger_regulator'. The only reason that it worked is
because both 'supply' and 'regulator_name' struct members are the
first in these structs. :-)

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>