[CPUFREQ] fix powernow-k8 compilation [bug 3180]

Propagate the new CONFIG_X86_POWERNOW_K8_ACPI to powernow-k8.h to avoid
compile breakage. Fixes bug 3180.
Signed-off-by: Dominik Brodowski <linux@brodo.de>
Signed-off-by: Dave Jones <davej@redhat.com>

arch/i386/kernel/cpu/cpufreq/powernow-k8.h

@@ -29,7 +29,7 @@ struct powernow_k8_data {
 	 * frequency is in kHz */
 	struct cpufreq_frequency_table  *powernow_table;
 
-#if defined(CONFIG_ACPI_PROCESSOR) || defined(CONFIG_ACPI_PROCESSOR_MODULE)
+#ifdef CONFIG_X86_POWERNOW_K8_ACPI
 	/* the acpi table needs to be kept. it's only available if ACPI was
 	 * used to determine valid frequency/vid/fid states */
 	struct acpi_processor_performance acpi_data;