mv64361: Remove extra break from a switch case

mv64361: Remove extra break from a switch case

The switch case of writing PCI 1 IO base address had an extra break
statement that made part of the code unreachable. This did not cause a
problem as guests ususally leave this register at its default value.

Fixes: dcdf98a9015 ("Add emulation of Marvell MV64361 PPC system
       controller")
Reported-by: Coverity (CID 1458135)
Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Message-Id: <20210712131259.B705B7456E3@zero.eik.bme.hu>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>