Fixes following warning during the boot:
WARNING: Variable 'led' does not exist or is not an array/object
Signed-off-by: Petr Štetiar <ynezz@true.cz>
(cherry picked from commit 5816caad26ae294f0adb4ed07ed53dcba7277c33)
Based on a patch from Chris Blake <chrisrblake93@gmail.com>, except let's
do it by using the LED configuration instead of hard-coding it for each
board type. And try using /bin/board_detect to do the default behaviour,
on the first boot where the config hasn't yet been generated.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>