x86: coral: Add sysinfo ops

These ops are missing at present which is not permitted. Add an empty
operation struct.

Note: If the uclass requires operations then the drivers should provide
them. Otherwise, checking for missing operations must be done in every
uclass operation, so it adds to code size.

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