firewire: mark some structs const

Instances of struct file_operations and struct fw_card_driver can be
qualified as "const".  Ditto with struct fw_descriptor.data, struct
fw_device_id, and predefined instances of struct fw_address_region,
at least in the current implementation.

Data qualified as const is placed into the .rodata section which won't
be mixed with dirty data.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

drivers/firewire/fw-card.c

@@ -257,7 +257,7 @@ flush_timer_callback(unsigned long data)
 }
 
 void
-fw_card_initialize(struct fw_card *card, struct fw_card_driver *driver,
+fw_card_initialize(struct fw_card *card, const struct fw_card_driver *driver,
 		   struct device *device)
 {
 	static int index;