The qemu debugcon port returns 0xe9 on reads in case the device is
present. Use that for detection and write console output to the
port only in case the device is actually present.
Change-Id: I41aabcf11845d24004e4f795dfd799822fd14646
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-on: http://review.coreboot.org/3338
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
