cpufreq: merge 'if' blocks in __cpufreq_remove_dev_prepare()

There are two 'if' blocks here, checking for !cpufreq_driver->setpolicy and
has_target(). Both are actually doing the same thing, merge them.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>