ledflasher: Use lights HAL if it is available.

Change the ledflasher to use the lights hal if it is available. If the
lights hal isn't available, then it defaults back to using sysfs.

Remove a CHECK from ledflasher.cpp as a short term fix. Added a TODO
there for a longer term solution.

TEST=manual test on both the edison and dragonboard

Change-Id: I6b2d57ff61bde7a2c7ec31fc744871240ad9f83d
4 files changed