m68knommu: fix clock rate value reported for ColdFire 54xx parts

The instruction timings of the ColdFire 54xx family parts are
different to other version 4 parts (or version 2 or 3 parts for
that matter too).

Move the instruction timing setting into the ColdFire part
specific headers, and set the 54xx value appropriately.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
diff --git a/arch/m68k/include/asm/m5407sim.h b/arch/m68k/include/asm/m5407sim.h
index 1de44c5..e07d4d8 100644
--- a/arch/m68k/include/asm/m5407sim.h
+++ b/arch/m68k/include/asm/m5407sim.h
@@ -14,7 +14,8 @@
 #define	m5407sim_h
 /****************************************************************************/
 
-#define	CPU_NAME	"COLDFIRE(m5407)"
+#define	CPU_NAME		"COLDFIRE(m5407)"
+#define	CPU_INSTR_PER_JIFFY	3
 
 /*
  *	Define the 5407 SIM register set addresses.