cpufreq/amd-pstate: Call cppc_set_auto_sel() only for online CPUs

amd_pstate_change_mode_without_dvr_change() calls cppc_set_auto_sel()
for all the present CPUs.

However, this callpath eventually calls cppc_set_reg_val() which
accesses the per-cpu cpc_desc_ptr object. This object is initialized
only for online CPUs via acpi_soft_cpu_online() -->
__acpi_processor_start() --> acpi_cppc_processor_probe().

Hence, restrict calling cppc_set_auto_sel() to only the online CPUs.

Fixes: 3ca7bc818d8c ("cpufreq: amd-pstate: Add guided mode control support via sysfs")
Suggested-by: Mario Limonciello (AMD) (kernel.org) <[e-mail]>
Signed-off-by: Gautham R. Shenoy <[e-mail]>
Signed-off-by: Mario Limonciello (AMD) <[e-mail]>

drivers/cpufreq/amd-pstate.c

···
 	if (cpu_feature_enabled(X86_FEATURE_CPPC) || cppc_state == AMD_PSTATE_ACTIVE)
 		return 0;
 
-	for_each_present_cpu(cpu) {
+	for_each_online_cpu(cpu) {
 		cppc_set_auto_sel(cpu, (cppc_state == AMD_PSTATE_PASSIVE) ? 0 : 1);
 	}