powernow-k6: reorder frequencies

commit 22c73795b101597051924556dce019385a1e2fa0 upstream.

This patch reorders reported frequencies from the highest to the lowest,
just like in other frequency drivers.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
[bwh: Backported to 3.2: cpu_frequency_table::driver_data is called index]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>