dm: x86: Add a driver for Intel PCH9

At some point we may need to distinguish between different types of PCHs,
but for existing supported platforms we only need to worry about version 7
and version 9 bridges. Add a driver for the PCH9.

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