acpi: make ACPI device id constant

The ids field of the struct acpi_driver is constant in <linux/acpi/acpi_bus.h>
so it is worth to make the initialization data also constant.

The semantic match that finds this kind of pattern is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r@
disable decl_init,const_decl_init;
identifier I1, I2, x;
@@
	struct I1 {
	  ...
	  const struct I2 *x;
	  ...
	};
@s@
identifier r.I1, y;
identifier r.x, E;
@@
	struct I1 y = {
	  .x = E,
	};
@c@
identifier r.I2;
identifier s.E;
@@
	const struct I2 E[] = ... ;
@depends on !c@
identifier r.I2;
identifier s.E;
@@
+	const
	struct I2 E[] = ...;
// </smpl>
Signed-off-by: NMárton Németh <nm127@freemail.hu>
Cc: Julia Lawall <julia@diku.dk>
Cc: cocci@diku.dk
Signed-off-by: NLen Brown <len.brown@intel.com>

drivers/acpi/pci_link.c

@@ -56,7 +56,7 @@ ACPI_MODULE_NAME("pci_link");
 static int acpi_pci_link_add(struct acpi_device *device);
 static int acpi_pci_link_remove(struct acpi_device *device, int type);
 
-static struct acpi_device_id link_device_ids[] = {
+static const struct acpi_device_id link_device_ids[] = {
 	{"PNP0C0F", 0},
 	{"", 0},
 };

drivers/acpi/pci_root.c

@@ -46,7 +46,7 @@ static int acpi_pci_root_add(struct acpi_device *device);
 static int acpi_pci_root_remove(struct acpi_device *device, int type);
 static int acpi_pci_root_start(struct acpi_device *device);
 
-static struct acpi_device_id root_device_ids[] = {
+static const struct acpi_device_id root_device_ids[] = {
 	{"PNP0A03", 0},
 	{"", 0},
 };

drivers/acpi/power.c

@@ -65,7 +65,7 @@ static int acpi_power_remove(struct acpi_device *device, int type);
 static int acpi_power_resume(struct acpi_device *device);
 static int acpi_power_open_fs(struct inode *inode, struct file *file);
 
-static struct acpi_device_id power_device_ids[] = {
+static const struct acpi_device_id power_device_ids[] = {
 	{ACPI_POWER_HID, 0},
 	{"", 0},
 };

drivers/acpi/power_meter.c

@@ -64,7 +64,7 @@ static int can_cap_in_hardware(void)
 	return force_cap_on || cap_in_hardware;
 }
 
-static struct acpi_device_id power_meter_ids[] = {
+static const struct acpi_device_id power_meter_ids[] = {
 	{"ACPI000D", 0},
 	{"", 0},
 };