sh: Fix bogus regs pointer in do_IRQ().

SH-3 and SH-4 were trampling the register, and SH-2 wasn't even
setting it in the first place. This ended up with some rather
broken behaviour in the sysrq show_regs().

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/include/asm-sh/irq.h b/include/asm-sh/irq.h
index 8ccf7ae..afe188f 100644
--- a/include/asm-sh/irq.h
+++ b/include/asm-sh/irq.h
@@ -94,8 +94,13 @@
 /*
  * Convert back and forth between INTEVT and IRQ values.
  */
+#ifdef CONFIG_CPU_HAS_INTEVT
 #define evt2irq(evt)		(((evt) >> 5) - 16)
 #define irq2evt(irq)		(((irq) + 16) << 5)
+#else
+#define evt2irq(evt)		(evt)
+#define irq2evt(irq)		(irq)
+#endif
 
 /*
  * Simple Mask Register Support