[MIPS] rbhma4500: use generic txx9 gpio

Use generic txx9 gpio (and gpiolib) for RBHMA4500 board.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index f4c313f..abc485d 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -654,7 +654,7 @@
 	select SYS_SUPPORTS_BIG_ENDIAN
 	select SYS_SUPPORTS_KGDB
 	select GENERIC_HARDIRQS_NO__DO_IRQ
-	select GENERIC_GPIO
+	select GPIO_TXX9
 	help
 	  This Toshiba board is based on the TX4938 processor. Say Y here to
 	  support this machine type