cpufreq: CPPC: Avoid overflow when calculating desired_perf

This patch fixes overflow issue when calculating the desired_perf.

Fixes: ad38677 (cpufreq: CPPC: Force reporting values in KHz to fix user space interface)
Signed-off-by: Hoan Tran <hotran@apm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpufreq/cppc_cpufreq.c

@@ -84,7 +84,7 @@ static int cppc_cpufreq_set_target(struct cpufreq_policy *policy,
 
 	cpu = all_cpu_data[policy->cpu];
 
-	cpu->perf_ctrls.desired_perf = target_freq * policy->max / cppc_dmi_max_khz;
+	cpu->perf_ctrls.desired_perf = (u64)target_freq * policy->max / cppc_dmi_max_khz;
 	freqs.old = policy->cur;
 	freqs.new = target_freq;