Only reference this function when the kconfig makes it available.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

arch/x86/kernel/cpu/cpufreq/powernow-k7.c

@@ -717,7 +717,9 @@ static struct cpufreq_driver powernow_driver = {
 	.verify		= powernow_verify,
 	.target		= powernow_target,
 	.get		= powernow_get,
+#ifdef CONFIG_X86_POWERNOW_K7_ACPI
 	.bios_limit	= acpi_processor_get_bios_limit,
+#endif
 	.init		= powernow_cpu_init,
 	.exit		= powernow_cpu_exit,
 	.name		= "powernow-k7",