UPSTREAM: serial: Add Darwin/macOS support for custom and >230400 baudrates This change is based on the patch proposed by Denis Ahrens in https://review.coreboot.org/c/flashrom/+/67822 (cherry picked from commit 03c36be3b6cd8666a63bfa8207a8123c49404a8d) Original-Change-Id: I3e6b88d2b4c2a130b16456752681fd9f807bf6f0 Original-Signed-off-by: Peter Stuge <peter@stuge.se> Original-Reviewed-on: https://review.coreboot.org/c/flashrom/+/70571 Original-Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Original-Reviewed-by: Thomas Heijligen <src@posteo.de> GitOrigin-RevId: 03c36be3b6cd8666a63bfa8207a8123c49404a8d Change-Id: I93f589d03227db7e512eb5c62de20a042a63f454 Signed-off-by: CopyBot <copybot.service@gmail.com> Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/flashrom/+/4261800 Commit-Queue: Edward O'Callaghan <quasisec@chromium.org> Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>