HACK: lights: don't allow setting brightness to zero

Workaround display backlight being off on first boot, not sure what
other impacts this will have, needs to be fixed properly
diff --git a/liblight/lights.c b/liblight/lights.c
index c62182f..08432d5 100644
--- a/liblight/lights.c
+++ b/liblight/lights.c
@@ -110,6 +110,8 @@
     }
 
     int brightness = rgb_to_brightness(state) << 2; // Scale up to 1020
+    ALOGI("CA:: Writing brightness: %d\n", brightness);
+    brightness = brightness ?: 1 << 2; // Don't allow 0 brightness
     write_brightness(brightness);
 
     return 0;