MIPS: Sanitise Cavium switch cases in TLB handler synthesizers

It makes no sense to fall through to `break'.  Therefore reorder the
switch statements so as to have the Cavium cases first, followed by the
default case, which improves readability and pacifies code analysis
tools.  No change in semantics, assembly produced is exactly the same.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Fixes: bc431d21 ("MIPS: Fix fall-through warnings for Clang")
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>