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-sbp2.c b/drivers/firewire/fw-sbp2.c
index ce9c41f..28acae8 100644
--- a/drivers/firewire/fw-sbp2.c
+++ b/drivers/firewire/fw-sbp2.c
@@ -681,7 +681,7 @@
 #define SBP2_UNIT_SPEC_ID_ENTRY	0x0000609e
 #define SBP2_SW_VERSION_ENTRY	0x00010483
 
-static struct fw_device_id sbp2_id_table[] = {
+static const struct fw_device_id sbp2_id_table[] = {
 	{
 		.match_flags  = FW_MATCH_SPECIFIER_ID | FW_MATCH_VERSION,
 		.specifier_id = SBP2_UNIT_SPEC_ID_ENTRY,