device-google-peach-{pit,pi}: use ttySAC3 for getty and console

For some reason kernel does not print anything to ttySAC3 even with console=/dev/ttySAC3. If earlycon is specified it prints the early stuff though.

Add ttySAC3 in both places anyways since that should be the correct uart. Only tested on peach-pit, but should be the same.

Getty works without issues.