cpufreq: mt8173: Move resources allocation into ->probe()

Since the return value of ->init() of cpufreq driver is not propagated
to the device driver model now, move resources allocation into
->probe() to handle -EPROBE_DEFER properly.

Signed-off-by: Pi-Cheng Chen <pi-cheng.chen@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>