MIPS: Sibyte: Fix build error if CONFIG_SERIAL_SB1250_DUART is undefined.

This fixes kernel.org bugzilla 13596, see
http://bugzilla.kernel.org/show_bug.cgi?id=13596

Reported-by: dvice_null@yahoo.com

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
1 file changed