ARM: ux500: Disable Power Supply and Battery Management by default

The AB8500 Battery Management collection of drivers are more than a
little bit broken. There is lots of work still on-going in that area
and it's improving day by day; however, it's not ready to be enabled
by default just yet.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>