sh: asm/irq.h needs asm/cpu/irq.h.

The SH-5 build currently fails when trying to build the i8042 code due
to the missing IRQ definitions. These are provided in asm/cpu/irq.h, so
just include that there to get it building again.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/include/asm-sh/irq.h b/include/asm-sh/irq.h
index 11850f6..ca66e5d 100644
--- a/include/asm-sh/irq.h
+++ b/include/asm-sh/irq.h
@@ -50,4 +50,8 @@
 # define irq_ctx_exit(cpu) do { } while (0)
 #endif
 
+#ifdef CONFIG_CPU_SH5
+#include <asm/cpu/irq.h>
+#endif
+
 #endif /* __ASM_SH_IRQ_H */