This should allow FireWire charging to work on these devices.
It also adds charging state detection on the iPod Classic.
(cherry picked from commit fa86fec4fb)
On Classic (and probably Nano 2G), it seems that the 100/500mA limit
applies only to USB chargers, when FW is connected it supplies all the
power (even if USB is also connected) and USB current limit does not
affect to FW charging, therefore the limit is only set when USB is
connected.
Change-Id: I7c6bab1b6a0f295367999c45faeda6085c3fb091
Signed-off-by: Cástor Muñoz <cmvidal@gmail.com>
bc56811a0e