Build - Define CONFIG_64BIT for LP64 target

Linux kernel uapi headers use CONFIG_64BIT flag. We need to define that
if
__LP64__ flag is defined.

Change-Id: I782aa78782fe394571df594b7c3d24b44965df60
Signed-off-by: STELIX <ssspinni@gmail.com>
Build - Add support for device tree in boot.img

Add support for optional device tree image (dt.img)
to boot and recovery images.  Some devices use kernel device
tree and this adds the device tree image as a section within
the boot/recovery images.

Change-Id: I36bf6feb976df84744889054661626176d0d6eaf
Signed-off-by: STELIX <ssspinni@gmail.com>