m68knommu: rework definition of HZ

Rework the HZ definition to be more consistent with other architectures.
Non-kernel includers will see a constant HZ setting of 100.
Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/asm-m68knommu/param.h

 #ifndef _M68KNOMMU_PARAM_H
 #define _M68KNOMMU_PARAM_H
 
-#define HZ CONFIG_HZ
-
 #ifdef __KERNEL__
+#define HZ CONFIG_HZ
 #define	USER_HZ		HZ
 #define	CLOCKS_PER_SEC	(USER_HZ)
 #endif
 
+#ifndef HZ
+#define HZ	100
+#endif
+
 #define EXEC_PAGESIZE	4096
 
 #ifndef NOGROUP