cpufreq: ti: Use generic platdev driver

Now that the cpufreq-dt-platdev is used to create the cpufreq-dt platform
device for all OMAP platforms and the platform code that did it
before has been removed, add ti,am33xx and ti,dra7xx to the machine list
in cpufreq-dt-platdev which had relied on the removed platform code to do
this previously.

Fixes: 7694ca6e (cpufreq: omap: Use generic platdev driver)
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: 4.7+ <stable@vger.kernel.org> # 4.7+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>