[MIPS] The irq_chip for TX39/TX49 SoCs

Add generic irq_chip for TX39/TX49 SoCs.  This can be replace
jmr3927_irq_irc, tx4927_irq_pic_type and tx4938_irq_pic_type.

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 2775dd6..cec0d84 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -767,6 +767,9 @@
 config IRQ_MSP_CIC
 	bool
 
+config IRQ_TXX9
+	bool
+
 config MIPS_BOARDS_GEN
 	bool