leds: qti-flash: Do not define "trigger_to_lcdev" function

Remove "trigger_to_lcdev" function definition from "leds-qti-flash"
driver file as the same is present in "leds.h" file and leads to a
compilation error.

Change-Id: Idea49767911f3a57b72bd1560d9ef485d16de25f
Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>