[MIPS] Sibyte: CONFIG_SIBYTE_SB1250_DUART -> CONFIG_SERIAL_SB1250_DUART

This is needed since the Sibyte serial driver was exchanged.

Issue report by Imre Kaloz <kaloz@openwrt.org>.

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