mkbootimg: Add --dt parameter to specify DT image

New optional --dt parameter to specify a kernel device
tree image.

Change-Id: I7e2c48c25c04165642eedadc3dc16a082dd99eb0
init: uevent: Add msm video symbolic link handling

Create meaningful symbolic links for video encode/decode
devices based on link_name sysfs node so that video client
doesn't have to rely on dynamic dev node names like device32,
device33 etc.

Change-Id: I70386351d83b8a7a7a690378870eee87f4c96983