Use new txx9 serial driver.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 455de42..41d782e 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -635,6 +635,7 @@
 	select OWN_DMA
 	select DMA_IP32
 	select DMA_NONCOHERENT
+	select HAS_TXX9_SERIAL
 	select HW_HAS_PCI
 	select R5000_CPU_SCACHE
 	select RM7000_CPU_SCACHE
@@ -814,6 +815,7 @@
 
 config RWSEM_XCHGADD_ALGORITHM
 	bool
+	select HAS_TXX9_SERIAL
 
 config GENERIC_CALIBRATE_DELAY
 	bool