x86: Add an option to include a FIT

Many Intel SoCs require a FIT in order to boot properly. Add an option to
include this and enable it by default.

This term can be confused with FIT (Flat Image Tree) in U-Boot so the
CONFIG option has to include 'X86'.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2 files changed