Increase HZ_VM from 10 to 100. While 10 hz saves cpu time

under VM environments, it's too slow for FreeBSD to work
properly.  For example, ping at 10hz pings about every 600ms
instead of about every second.

Approved by:	re (kib)

sys/kern/subr_param.c

@@ -58,7 +58,7 @@ __FBSDID("$FreeBSD$");
 #    define	HZ 100
 #  endif
 #  ifndef HZ_VM
-#    define	HZ_VM 10
+#    define	HZ_VM 100
 #  endif
 #else
 #  ifndef HZ_VM