Support of legacy 64-bit entry point was already present when booting a bzimage
with 'zboot' but not supported with 'bootm' when the x86_64 Linux kernel is
embedded in a FIT image.
Signed-off-by: Paul HENRYS <paul.henrys_ext@softathome.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
(cherry picked from commit 37f0c32ca2)