pointer freq_table can be made static as it does not need to be in
global scope.

Cleans up sparse warning:
"symbol 'freq_table' was not declared. Should it be static?"
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>