U-Boot proper expects its FDT to be right after its binary image; the
"full" FIT image loader thus adopts an hack to relocate it, ignoring
the specified load address.
Rework the current form of the hack to:
- support the 'sandbox' environment with a sysmem-aware memcpy;
- use the ALIGN() macro instead of raw alignment logic;
- align the FDT to 8-byte boundary as per FDT specifications;
- fix the debug print (which was reporting the source address for the
relocation instead of the destination one).
Signed-off-by: Francesco Valla <francesco@valla.it>