In the memory map of the documentation the kernel only had 16MiB of
allocated space. This leaves very little room for growth, so the
addresses of the DTB and the kernel have been interchanged.

The documentation has been updated to reflect this change.

Change-Id: Ib6eab69f047fa88561fb755397ce3a0b356c8860
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>