cpufreq: rename index as driver_data in cpufreq_frequency_table

The "index" field of struct cpufreq_frequency_table was never an
index and isn't used at all by the cpufreq core.  It only is useful
for cpufreq drivers for their internal purposes.

Many people nowadays blindly set it in ascending order with the
assumption that the core will use it, which is a mistake.

Rename it to "driver_data" as that's what its purpose is. All of its
users are updated accordingly.

[rjw: Changelog]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpufreq/powernow-k6.c

@@ -58,7 +58,7 @@ static int powernow_k6_get_cpu_multiplier(void)
 	msrval = POWERNOW_IOPORT + 0x0;
 	wrmsr(MSR_K6_EPMR, msrval, 0); /* disable it again */
 
-	return clock_ratio[(invalue >> 5)&7].index;
+	return clock_ratio[(invalue >> 5)&7].driver_data;
 }
 
 
@@ -75,13 +75,13 @@ static void powernow_k6_set_state(struct cpufreq_policy *policy,
 	unsigned long msrval;
 	struct cpufreq_freqs freqs;
 
-	if (clock_ratio[best_i].index > max_multiplier) {
+	if (clock_ratio[best_i].driver_data > max_multiplier) {
 		printk(KERN_ERR PFX "invalid target frequency\n");
 		return;
 	}
 
 	freqs.old = busfreq * powernow_k6_get_cpu_multiplier();
-	freqs.new = busfreq * clock_ratio[best_i].index;
+	freqs.new = busfreq * clock_ratio[best_i].driver_data;
 
 	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
 
@@ -156,7 +156,7 @@ static int powernow_k6_cpu_init(struct cpufreq_policy *policy)
 
 	/* table init */
 	for (i = 0; (clock_ratio[i].frequency != CPUFREQ_TABLE_END); i++) {
-		f = clock_ratio[i].index;
+		f = clock_ratio[i].driver_data;
 		if (f > max_multiplier)
 			clock_ratio[i].frequency = CPUFREQ_ENTRY_INVALID;
 		else