clocksource, sparc32: Convert to using clocksource_register_hz()

While cleaning up some clocksource code, I noticed the
time_32 implementation uses the clocksource_hz2mult()
helper, but doesn't use the clocksource_register_hz()
method.

I don't believe the Sparc clocksource is a default
clocksource, so we shouldn't need to self-define
the mult/shift pair.

So convert the time_32.c implementation to use
clocksource_register_hz().

Untested.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1426133800-29329-11-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>