PM / ACPI: Remove references to pm_flags from bus.c

If direct references to pm_flags are removed from drivers/acpi/bus.c,
CONFIG_ACPI will not need to depend on CONFIG_PM any more.  Make that
happen.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Len Brown <len.brown@intel.com>
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 7018530..b5405af 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -17,10 +17,20 @@
 
 DEFINE_MUTEX(pm_mutex);
 
+#ifdef CONFIG_PM_SLEEP
+
 unsigned int pm_flags;
 EXPORT_SYMBOL(pm_flags);
 
-#ifdef CONFIG_PM_SLEEP
+bool pm_apm_enabled(void)
+{
+	return !!(pm_flags & PM_APM);
+}
+
+void pm_set_acpi_flag(void)
+{
+	pm_flags |= PM_ACPI;
+}
 
 /* Routines for PM-transition notifications */