powerpc: make of_device_ids const

of_device_ids (i.e. compatible strings and the respective data) are not
supposed to change at runtime. All functions working with of_device_ids
provided by <linux/of.h> work with const of_device_ids. This allows to
mark all struct of_device_id const, too.

While touching these line also put the __init annotation at the right
position where necessary.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/sysdev/mv64x60_dev.c

@@ -23,7 +23,7 @@
 
 /* These functions provide the necessary setup for the mv64x60 drivers. */
 
-static struct of_device_id __initdata of_mv64x60_devices[] = {
+static const struct of_device_id of_mv64x60_devices[] __initconst = {
 	{ .compatible = "marvell,mv64306-devctrl", },
 	{}
 };