sh: Tidy up duplication in irq/swab/timex.h.

The asm-generic versions have some helper definitions that we can use
instead, drop our definitions and use those instead.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/sh/include/asm/irq.h b/arch/sh/include/asm/irq.h
index a2b8c99..df8e150 100644
--- a/arch/sh/include/asm/irq.h
+++ b/arch/sh/include/asm/irq.h
@@ -39,7 +39,6 @@
 	return irq;
 }
 
-#define irq_canonicalize(irq)	(irq)
 #define irq_demux(irq)		sh_mv.mv_irq_demux(irq)
 
 void init_IRQ(void);
@@ -54,6 +53,7 @@
 # define irq_ctx_exit(cpu) do { } while (0)
 #endif
 
+#include <asm-generic/irq.h>
 #ifdef CONFIG_CPU_SH5
 #include <cpu/irq.h>
 #endif