firewire: replace more hex values with defined csr constants

Trivial change to replace more meaningless (to the untrained eye) hex
values with defined CSR constants.

Signed-off-by: Jarod Wilson <jwilson@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/firewire/fw-device.c b/drivers/firewire/fw-device.c
index 75365cd..2d01bc1 100644
--- a/drivers/firewire/fw-device.c
+++ b/drivers/firewire/fw-device.c
@@ -410,7 +410,7 @@
 
 	init_completion(&callback_data.done);
 
-	offset = 0xfffff0000400ULL + index * 4;
+	offset = (CSR_REGISTER_BASE | CSR_CONFIG_ROM) + index * 4;
 	fw_send_request(device->card, &t, TCODE_READ_QUADLET_REQUEST,
 			device->node_id, generation, device->max_speed,
 			offset, NULL, 4, complete_transaction, &callback_data);