parisc: math-emu: Fix fall-through warnings

commit 6f1fce59 upstream.

Fix lots of fallthrough warnings, e.g.:
arch/parisc/math-emu/fpudispatch.c:323:33: warning: this statement may fall through [-Wimplicit-fallthrough=]

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>