LED/MIPS: Move SEAD3 LED driver to where it belongs.

Fixes the following randconfig problem

leds-sead3.c:(.text+0x7dc): undefined reference to `led_classdev_unregister'
leds-sead3.c:(.text+0x7e8): undefined reference to `led_classdev_unregister'

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Bryan Wu <cooloney@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-leds@vger.kernel.org
Cc: linux-mips@linux-mips.org
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>