ARM: dts: msm: Add led flash support for Kona platforms

Flash led source needs to be a part of image sensor in order to
use the LED functionality. This change adds appropriate flash LED
source to respective image sensor.

Change-Id: I54b4ef58eb4d998399a105aa2614ffcc9f84b129
Signed-off-by: Pengfei Liu <pengfeiliu@codeaurora.org>