m68k: Remove the 030 case in virt_to_phys_slow

The 030 case in virt_to_phys_slow can't ever be reached, so remove it.

Suggested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Michael Schmitz <schmitzmic@gmail.com>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Link: https://lore.kernel.org/r/20210916070405.52750-3-hch@lst.de


Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>