cpufreq: mediatek: add mediatek related projects into blacklist

mediatek projects will use mediate-cpufreq.c as cpufreq driver,
instead of using cpufreq_dt.c
Add mediatek related projects into cpufreq-dt blacklist

Signed-off-by: Andrew-sh Cheng <andrew-sh.cheng@mediatek.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>