Many common initializations of struct policy are moved to core now and hence
this driver doesn't need to do it. This patch removes such code.

Most recent of those changes is to call ->get() in the core after calling
->init(). And so we don't need to set policy->cur from driver anymore.

Over that it sets policy->min and max correctly. They were earlier set to
current frequency of CPU but they should be set to max and min freq of cpu.

Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>