Sockeye: Switch default mapping to 0x0 if no base address given
Sockeye: Switch default mapping to 0x0 if no base address given

Signed-off-by: Daniel Schwyn <f879f85f8944da78bc552a4183a20366c1fe8f48@student.ethz.ch>

BarrelfishOS/barrelfish,BarrelfishOS/barrelfish,BarrelfishOS/barrelfish,kishoredbn/barrelfish,BarrelfishOS/barrelfish,kishoredbn/barrelfish,kishoredbn/barrelfish,kishoredbn/barrelfish,BarrelfishOS/barrelfish,kishoredbn/barrelfish,BarrelfishOS/barrelfish,BarrelfishOS/barrelfish,BarrelfishOS/barrelfish,BarrelfishOS/barrelfish,kishoredbn/barrelfish