Input: sparcspkr - avoid unannotated fall-through

Fix follow warnings with clang-21i (and reformat for clarity):
  drivers/input/misc/sparcspkr.c:78:3: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
     78 |                 case SND_TONE: break;
        |                 ^
  drivers/input/misc/sparcspkr.c:78:3: note: insert 'break;' to avoid fall-through
     78 |                 case SND_TONE: break;
        |                 ^
        |                 break;
  drivers/input/misc/sparcspkr.c:113:3: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
    113 |                 case SND_TONE: break;
        |                 ^
  drivers/input/misc/sparcspkr.c:113:3: note: insert 'break;' to avoid fall-through
    113 |                 case SND_TONE: break;
        |                 ^
        |                 break;
  2 warnings generated.

Signed-off-by: WangYuli <wangyuli@uniontech.com>
Link: https://lore.kernel.org/r/6730E40353C76908+20250415052439.155051-1-wangyuli@uniontech.com


Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>