twl4030_bci_battery.c is now moved to new style
registration of twl4030 children.

During the process a few bugfixes came, the main one
is that twl4030-bci was releasing the wrong irq if
battery registration had failed.
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>