LEDS: add initial support for WS2801 controller (PandaBoard) This adds initial support for the WS2801 RGB LED controller on the beaconboard for the Panda Board
This patch fixs one performance bug on ARM Cortex A9 dual core platform, which has been reported on quite a few ARM machines (OMAP4, Tegra 2, snowball...), see details from link of https://bugs.launchpad.net/bugs/709245.