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/m68knommu/kernel/setup.c b/arch/m68knommu/kernel/setup.c
index f48d9df..5c931f9 100644
--- a/arch/m68knommu/kernel/setup.c
+++ b/arch/m68knommu/kernel/setup.c
@@ -66,13 +66,20 @@
 #ifdef CONFIG_M68360
 #define CPU_NAME	"MC68360"
 #endif
-/*
- * The ColdFire CPU names are defined in their headers.
- */
 #ifndef CPU_NAME
 #define	CPU_NAME	"UNKNOWN"
 #endif
 
+/*
+ * Different cores have different instruction execution timings.
+ * The old/traditional 68000 cores are basically all the same, at 16.
+ * The ColdFire cores vary a little, their values are defined in their
+ * headers. We default to the standard 68000 value here.
+ */
+#ifndef CPU_INSTR_PER_JIFFY
+#define	CPU_INSTR_PER_JIFFY	16
+#endif
+
 extern int _stext, _etext, _sdata, _edata, _sbss, _ebss, _end;
 extern int _ramstart, _ramend;
 
@@ -273,12 +280,7 @@
 	cpu = CPU_NAME;
 	mmu = "none";
 	fpu = "none";
-
-#ifdef CONFIG_COLDFIRE
-	clockfreq = (loops_per_jiffy * HZ) * 3;
-#else
-	clockfreq = (loops_per_jiffy * HZ) * 16;
-#endif
+	clockfreq = (loops_per_jiffy * HZ) * CPU_INSTR_PER_JIFFY;
 
 	seq_printf(m, "CPU:\t\t%s\n"
 		      "MMU:\t\t%s\n"