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>

include/asm-sh/irq.h

@@ -50,4 +50,8 @@ extern void irq_ctx_exit(int cpu);
 # define irq_ctx_exit(cpu) do { } while (0)
 #endif
 
+#ifdef CONFIG_CPU_SH5
+#include <asm/cpu/irq.h>
+#endif
+
 #endif /* __ASM_SH_IRQ_H */