ARM: s3c: add one more "fallthrough" statement in Jive

clang warns about one missing fallthrough that gcc ignores:

arch/arm/mach-s3c/mach-jive.c:250:2: error: unannotated fall-through between switch labels [-Werror,-Wimplicit-fallthrough]

Add it here as well.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20211116092053.4042799-1-arnd@kernel.org


Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>