drivers: tty: 68328serial.c: Fix "foo * bar" should be "foo *bar"

This patch fixes checkpatch errors "foo * bar" should be "foo *bar".

Signed-off-by: Frederik Völkel <frederik.voelkel@fau.de>
Signed-off-by: Lukas Braun <lukas.braun@fau.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>