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>
diff --git a/drivers/firewire/fw-ohci.c b/drivers/firewire/fw-ohci.c
index 5d42d18..d3750a2 100644
--- a/drivers/firewire/fw-ohci.c
+++ b/drivers/firewire/fw-ohci.c
@@ -1146,7 +1146,7 @@
 	return 0;
 }
 
-static struct fw_card_driver ohci_driver = {
+static const struct fw_card_driver ohci_driver = {
 	.name			= ohci_driver_name,
 	.enable			= ohci_enable,
 	.update_phy_reg		= ohci_update_phy_reg,