[MIPS] JMR3927 cleanup

* Kill dead codes
* Rearrange irq chip handlers
* Minimize defconfig

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 2fd82e5..acceae0 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -779,6 +779,7 @@
 	select SYS_SUPPORTS_LITTLE_ENDIAN
 	select SYS_SUPPORTS_BIG_ENDIAN
 	select TOSHIBA_BOARDS
+	select GENERIC_HARDIRQS_NO__DO_IRQ
 
 config TOSHIBA_RBTX4927
 	bool "Toshiba TBTX49[23]7 board"