x86: Add support for private files

Some boards need to include binary data into the image for use during the
boot process. Add a node for these.

An example is the audio-codec configuration used by some audio drivers on
Intel platforms. If no private files are provided, they will be omitted.

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