MIPS/IRQCHIP: Move irq_chip from arch/mips to drivers/irqchip.

While at it, rename it because in drivers/irqchip no longer every CPU is
a MIPS.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index dda4927..129cde1 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -28,6 +28,7 @@
 obj-$(CONFIG_ATMEL_AIC_IRQ)		+= irq-atmel-aic-common.o irq-atmel-aic.o
 obj-$(CONFIG_ATMEL_AIC5_IRQ)	+= irq-atmel-aic-common.o irq-atmel-aic5.o
 obj-$(CONFIG_IMGPDC_IRQ)		+= irq-imgpdc.o
+obj-$(CONFIG_IRQ_MIPS_CPU)		+= irq-mips-cpu.o
 obj-$(CONFIG_SIRF_IRQ)			+= irq-sirfsoc.o
 obj-$(CONFIG_RENESAS_INTC_IRQPIN)	+= irq-renesas-intc-irqpin.o
 obj-$(CONFIG_RENESAS_IRQC)		+= irq-renesas-irqc.o