x86: cpu: Describe board final hooks in the header

The new two declarations board_final_init() and board_final_cleanup()
need a description. Add it here.

Suggested-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
1 file changed