cpufreq: ACPI: Only set boost MSRs on supported CPUs

Stop trying to set boost MSRs on CPUs that don't support boost.

This corrects a bug in the recent patch "Defer setting boost MSRs".

Fixes: 13fdbc8b ("cpufreq: ACPI: Defer setting boost MSRs")
Signed-off-by: Stuart Hayes <stuart.w.hayes@gmail.com>
Reported-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>