MIPS: Fix build for LTS kernel caused by backporting lpj adjustment

BugLink: https://bugs.launchpad.net/bugs/1888690

Commit ed26aacf ("mips: Add udelay lpj numbers adjustment")
has backported to 4.4~5.4, but the "struct cpufreq_freqs" (and also the
cpufreq notifier machanism) of 4.4~4.19 are different from the upstream
kernel. These differences cause build errors, and this patch can fix the
build.

Cc: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Stable <stable@vger.kernel.org> # 4.4/4.9/4.14/4.19
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

arch/mips/kernel/time.c

@@ -40,10 +40,8 @@ static unsigned long glb_lpj_ref_freq;
 static int cpufreq_callback(struct notifier_block *nb,
 			    unsigned long val, void *data)
 {
-	struct cpufreq_freqs *freq = data;
-	struct cpumask *cpus = freq->policy->cpus;
-	unsigned long lpj;
 	int cpu;
+	struct cpufreq_freqs *freq = data;
 
 	/*
 	 * Skip lpj numbers adjustment if the CPU-freq transition is safe for
@@ -64,6 +62,7 @@ static int cpufreq_callback(struct notifier_block *nb,
 		}
 	}
 
+	cpu = freq->cpu;
 	/*
 	 * Adjust global lpj variable and per-CPU udelay_val number in
 	 * accordance with the new CPU frequency.
@@ -74,12 +73,8 @@ static int cpufreq_callback(struct notifier_block *nb,
 						glb_lpj_ref_freq,
 						freq->new);
 
-		for_each_cpu(cpu, cpus) {
-			lpj = cpufreq_scale(per_cpu(pcp_lpj_ref, cpu),
-					    per_cpu(pcp_lpj_ref_freq, cpu),
-					    freq->new);
-			cpu_data[cpu].udelay_val = (unsigned int)lpj;
-		}
+		cpu_data[cpu].udelay_val = cpufreq_scale(per_cpu(pcp_lpj_ref, cpu),
+					   per_cpu(pcp_lpj_ref_freq, cpu), freq->new);
 	}
 
 	return NOTIFY_OK;