Upon resuming from sleep or swsusp, the ACPI P-States driver can't determine
the current CPU frequency, as the ACPI specification doesn't contain a method
to determine the current P-State.

Therefore, _always_ re-set the CPU to the P-State it was before suspending,
and don't abort early if this is the same state as the CPU was put to
before (like it does make sense when using the ondemand governor, for example).
Signed-off-by: Dominik Brodowski <linux@brodo.de>
Signed-off-by: Dave Jones <davej@redhat.com>