leds: remove use of __devexit_p

CONFIG_HOTPLUG is going away as an option so __devexit_p is no longer
needed.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Jan-Simon Moeller <jansimon.moeller@gmx.de>
Acked-by: Bryan Wu <cooloney@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>