[CPUFREQ] powernow-k6: set transition latency value so ondemand governor can be used

Set the transition latency to value smaller than CPUFREQ_ETERNAL so
governors other than "performance" work (like the "ondemand" one).

The value is found in "AMD PowerNow! Technology Platform Design Guide for
Embedded Processors" dated December 2000 (AMD doc #24267A). There is the
answer to one of FAQs on page 40 which states that suggested complete transition
period is 200 us.

Tested on K6-2+ CPU with K6-3 core (model 13, stepping 4).
Signed-off-by: NKrzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: NDave Jones <davej@redhat.com>

arch/x86/kernel/cpu/cpufreq/powernow-k6.c

@@ -164,7 +164,7 @@ static int powernow_k6_cpu_init(struct cpufreq_policy *policy)
 	}
 
 	/* cpuinfo and default policy values */
-	policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
+	policy->cpuinfo.transition_latency = 200000;
 	policy->cur = busfreq * max_multiplier;
 
 	result = cpufreq_frequency_table_cpuinfo(policy, clock_ratio);