defconfig: lito: Disable BUILD_ARM64_APPENDED_DTB_IMAGE flag

Add support to compile the kernel without the dtbs appended to it.
All the dtbs are concatenated to form dtb.img. Boot image with header
version 2 will now have this dtb.img added towards the end at an offset.

Change-Id: I66a5712fb9fda0795589be3f167678fd7b40d9c8
Signed-off-by: Gaurav Kohli <gkohli@codeaurora.org>