drivers/serial/s3c2440.c: fix typo in MODULE_LICENSE

Signed-off-by: Balaji Rao <balajirrao@gmail.com>
Acked-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>