[CPUFREQ] Make acpi-cpufreq 'sticky'.

This prevents annoying messages being printed when it gets
loaded on a machine that doesn't have support scaling via ACPI.
Signed-off-by: Dave Jones <davej@redhat.com>

arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c

@@ -451,6 +451,7 @@ static struct cpufreq_driver acpi_cpufreq_driver = {
 	.name	= "acpi-cpufreq",
 	.owner	= THIS_MODULE,
 	.attr	= acpi_cpufreq_attr,
+	.flags	= CPUFREQ_STICKY,
 };