x86: broadwell: Set up MTRRs

The current condition does not handle the samus_tpl case where it sets
up the RAM in SPL but needs to commit the MTRRs in U-Boot proper.

Add another case to handle this and update the comment.

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