cpufreq / intel_pstate: Change to disallow module build
Load order is important in order for intel_pstate to take over as the
default scaling driver from acpi-cpufreq.
If both are built-in, acpi-cpufreq uses late_initcall() and
intel_pstate uses device_initcall() so it will be able to register as
the scaling before acpi-cpufreq for the processors supported by
intel_pstate.
If acpi-cpufreq is built as a module then intel_pstate still gets
first option to become the scaling driver.
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>