[MIPS] Remove unused config entries

Signed-off-by: NYoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

arch/mips/Kconfig

@@ -841,15 +841,10 @@ config MIPS_TX3927
 config MIPS_RM9122
 	bool
 	select SERIAL_RM9000
-	select GPI_RM9000
-	select WDT_RM9000
 
 config PCI_MARVELL
 	bool
 
-config SERIAL_RM9000
-	bool
-
 config PNX8550
 	bool
 	select SOC_PNX8550
@@ -875,12 +870,6 @@ config EMMA2RH
 config SERIAL_RM9000
 	bool
 
-config GPI_RM9000
-	bool
-
-config WDT_RM9000
-	bool
-
 #
 # Unfortunately not all GT64120 systems run the chip at the same clock.
 # As the user for the clock rate and try to minimize the available options.