dm: serial: fix comment on dm_serial_ops setconfig

The comment on this function prototype describes nonexistent
parameters. It seems to be copied from 'setparity'.

Update it to match its the parameter list.

Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
1 file changed