This board was missed when converting all the others to proper
abstracted GPIO handling. Fix it up the right way by requesting
and driving GPIO line 0 high through gpiolib to power off the
machine.

Cc: Arnaud Patard <arnaud.patard@rtp-net.org>
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Olof Johansson <olof@lixom.net>