drivers: Remove Intel Enhanced SpeedStep driver

In current state this driver is useless anyway. It's not MP safe.
The P-state values stored in hardcoded tables are only for processors
on which we can't use SpeedStep, because of lack of invariant TSC.

Proper driver should get P-states from ACPI, ensure that the CPU offers
invariant TSC and obviouslt be MP safe.
preferences: Remove CPUFrequency

We can't reliably set contemporary processors to an arbitrary frequency.
There are dependencies between cores and thechnologies like Turbo Boost
which may make actual frequency significantly different than the requested.

Moreover, it is the scheduler job to decide how much CPU performance is
needed and user shouldn't interfere with that.
power: Remove old cpufreq interface