Add dual LED torch device to LM3644 driver

MSM camera framework only supports a single trigger for torch mode which
means that the same current/brightness value is used for dual LED torches
if two LED devices are hooked to the same trigger.

This change introduces a dual LED torch device that allows setting
different brightness values for the two LEDs in device tree.

Use dual LED torch trigger for new camera module

FPIIM-1300

Change-Id: I0693d645a14624bfd6b7a190b2e51f26b61d2179
2 files changed