mfd/power: ab8500: Push data to power supply code

The global definition of platform data for the battery
management code has no utility after the OF conversion,
move the <linux/mfd/abx500/ab8500-bm.h> to be a local
file in drivers/power/supply and stop defining the
platform data in drivers/power/supply/ab8500_bmdata.c
and broadcast to the kernel only to have it assigned
as platform data to the MFD cells and then picked back
into the same subsystem that defined it in the first
place. This kills off a layer of indirection.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>