[regression-mcs51] Use simif for output instead of serial port
treeeffb66acd8c154e8e831d0178b5edf498245e04f
drwxr-xr-x - sdcc-build
drwxr-xr-x - sdcc-cf
drwxr-xr-x - sdcc-extra
drwxr-xr-x - sdcc-web
drwxr-xr-x - sdcc