x86: i8254: Include required ibmpc.h header

This is needed for this file, so include it here explicitly.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> # Intel Edison
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
1 file changed