backlight control on Luna: switch PWL instead of LEDB This change is preliminary toward upcoming rework of backlight control logic in our UI firmware. LEDB does not exist on Tango-based platforms (it is not brought out on Tango modules), thus turning it on and off produces absolutely no effect beyond making L1 disable deep sleep when LEDB is turned on. However, both iWOW DSK and our upcoming FC Caramel2 boards have a PWL LED, so let's switch that LED on and off to indicate the state of the UI firmware's backlight control. Note that we are NOT switching the actual Luna LCD backlight here, even though it is trivially controlled with a GPIO. The reason for this seemingly strange choice is that we don't want to turn this development board LCD backlight off until we bring the higher-level backlight control logic up to par, including new logic to "swallow" the first keypress that turns on the darkened LCD.

/*
 * The only DSP patch code we have for 36_10 is the dynamic download version
 * which we have extracted from the world's last surviving copy of TCS211 fw
 * for Calypso modems.  The purpose of this cheesy patch_file36_10.c wrapper
 * is to allow experimental builds with L1_DYN_DSP_DWNLD=0: we use the static
 * portion of our only available patch code, and simply not do the dynamic part.
 *
 * This configuration is intended only for experiments, not for production!
 * The dynamic parts of the DSP patch code which this configuration omits
 * are surely there for some good reason, and we can only guess what we are
 * going to destabilize by disabling them.
 */

#include "patch_file36_10_dyn_dwl.c"