linux-imx

Documentation: leds-lp5521,lp5523: update device attribute information

Now, all legacy application interfaces are restored.
Each driver documentation is updated.

Cc: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Milo Kim <milo.kim@ti.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>