With this patch, the bq24022 battery charger is controlled by the USB
gadget framework (via gpio_vbus) when connected to USB.

To compile, this patch depends on the "regulator: Allow init data to be
supplied for bq24022" patch (queued for next in the regulator tree) to
add the init_data field to struct bq24022_mach_info.
It also depends on the "add optional OTG transceiver and voltage
regulator support to pda_power" patch (queued for next in the power
supply tree) to enable charging when connected to the AC charger.
Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Eric Miao <eric.miao@marvell.com>