ACPI: Schedule /proc/acpi/event for removal

Schedule /proc/acpi/event for removal in 6 months.

Re-name acpi_bus_generate_event() to acpi_bus_generate_proc_event()
to make sure there is no confusion that it is for /proc/acpi/event only.

Add CONFIG_ACPI_PROC_EVENT to allow removal of /proc/acpi/event.
There is no functional change if CONFIG_ACPI_PROC_EVENT=y

Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/asus_acpi.c b/drivers/acpi/asus_acpi.c
index 86fd142..d915fec 100644
--- a/drivers/acpi/asus_acpi.c
+++ b/drivers/acpi/asus_acpi.c
@@ -1069,7 +1069,7 @@
 		hotk->brightness = (event & ~((u32) BR_DOWN));
 	}
 
-	acpi_bus_generate_event(hotk->device, event,
+	acpi_bus_generate_proc_event(hotk->device, event,
 				hotk->event_count[event % 128]++);
 
 	return;