cpu governor: update interactive governor from grouper

   * Fix building with it
mach-tegra: disable INTERACTIVE_GOV_ON_EARLY_SUSPEND

   * By default let's use interactive gov
mach-tegra: honor tegra's EDP(electrical design limits)

   * This kinda necessary since we disabled HTC's best trade hotplug
LP5521 LED: Use a work queue for button backlight fading

The fading was implemented in a blocking way so that a change took around 200ms. This was
causing a noticeable input lag in the GUI because the buttons are dimmed when the user is
inactive and parts of the Android system wait for the liblights/LightsService call to
finish.

The time to change the brightness can be easily measured and verified with:

    time echo "255" > /sys/class/leds/button-backlight/brightness
Removing endeavoru lun_cdrom flag to let ums work rw instead of ro.

Change-Id: I62dcaba8dcd5055422c55f60f304b7fd8d2c27c1