sh: imask IRQ depends on sh32.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/kernel/cpu/irq/Makefile

 #
 # Makefile for the Linux/SuperH CPU-specifc IRQ handlers.
 #
-obj-y	+= imask.o intc.o
+obj-y	+= intc.o
 
+obj-$(CONFIG_SUPERH32)			+= imask.o
 obj-$(CONFIG_CPU_HAS_IPR_IRQ)		+= ipr.o
 obj-$(CONFIG_CPU_HAS_MASKREG_IRQ)	+= maskreg.o