x86: Move common fsp functions into a common file

Some of this file can be shared between FSP1 and FSP2. Move it into a
shared file.

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