cbtable.c: Resync physunmap semantics with upstream

BUG=chromium:478356
BRANCH=none
TEST=Ran `flashrom -p host --flash-name`.

Change-Id: If0b620107dd4bffaf0470c670ad02182e60bb02b
Signed-off-by: Edward O'Callaghan <quasisec@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/flashrom/+/1885855
Reviewed-by: Stefan Reinauer <reinauer@google.com>
1 file changed