ACPI: correct id for fixed buttons

ACPI_BUTTON_HID_POWERF was changed, but this change was not propogated to
button.c, thus breaking detection of fixed power and sleep buttons.
Signed-off-by: NAlexey Starikovskiy <alexey.y.starikovskiy@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLen Brown <len.brown@intel.com>

drivers/acpi/button.c

@@ -74,7 +74,7 @@ static int acpi_button_state_open_fs(struct inode *inode, struct file *file);
 static struct acpi_driver acpi_button_driver = {
 	.name = ACPI_BUTTON_DRIVER_NAME,
 	.class = ACPI_BUTTON_CLASS,
-	.ids = "ACPI_FPB,ACPI_FSB,PNP0C0D,PNP0C0C,PNP0C0E",
+	.ids = "button_power,button_sleep,PNP0C0D,PNP0C0C,PNP0C0E",
 	.ops = {
 		.add = acpi_button_add,
 		.remove = acpi_button_remove,