clocksource: m86k: Convert to clocksource_register_hz/khz

Updated to merge the valid bits of the two m68k patches.

This converts the m86k clocksources to use clocksource_register_hz/khz

This is untested, so any assistance in testing would be appreciated!

CC: Geert Uytterhoeven <geert@linux-m68k.org>
CC: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Greg Ungerer <gerg@uclinux.org>