CPUFREQ: Loongson2: drop set_cpus_allowed_ptr()

It is pure mystery to me why we need to be on a specific CPU while
looking up a value in an array.
My best shot at this is that before commit d4019f0a ("cpufreq: move
freq change notifications to cpufreq core") it was required to invoke
cpufreq_notify_transition() on a special CPU.

Since it looks like a waste, remove it.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: tglx@linutronix.de
Cc: linux-pm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/15888/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>