In preparation to enable -Wimplicit-fallthrough for Clang, fix multiple
warnings by explicitly adding multiple break statements instead of just
letting the code fall through, and also add fallthrough pseudo-keywords
in places where the code is intended to fall through to the next case.

Link: https://github.com/KSPP/linux/issues/115Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/d17b4d8300dbb6aff0d055b06b487c96ca264757.1605896059.git.gustavoars@kernel.orgSigned-off-by: Mark Brown <broonie@kernel.org>