rootdir: reduce permissions on /dev/rtc0

Remove world-readable, reduce group permissions to readable by system
daemons

Change-Id: I6c7d7d78b8d8281960659bb8490a01cf7fde28b4
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Add unpackbootimg.
mkbootimg: Add --dt parameter to specify DT image

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

Change-Id: I7e2c48c25c04165642eedadc3dc16a082dd99eb0

Conflicts:
	mkbootimg/mkbootimg.c

Conflicts:
	mkbootimg/mkbootimg.c
unpackbootimg: Add support for device trees

Change-Id: I340eed99d2274a2f4cbaf5a9f27726ff3a9302e5
Merge "rootdir: reduce permissions on /dev/rtc0"
auto-merger: merge in from aosp/master