x86/aperfmperf: Store aperf/mperf data for cpu frequency reads

Now that the MSR readout is unconditional, store the results in the per CPU
data structure along with a jiffies timestamp for the CPU frequency readout
code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20220415161206.817702355@linutronix.de