MIPS: bmips: Improve BCM6328 device tree

MIPS: bmips: Improve BCM6328 device tree

Adds bcm6328-leds node to bcm6328.dtsi

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Cc: jogo@openwrt.org
Cc: cernekee@gmail.com
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: Álvaro Fernández Rojas <noltari@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/12116/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>