tbbr/dualroot: Add fw_config image in chain of trust

fw_config image is authenticated using secure boot framework by
adding it into the single root and dual root chain of trust.

The COT for fw_config image looks as below:

+------------------+       +-------------------+
| ROTPK/ROTPK Hash |------>| Trusted Boot fw   |
+------------------+       | Certificate       |
                           | (Auth Image)      |
                          /+-------------------+
                         /                   |
                        /                    |
                       /                     |
                      /                      |
                     L                       v
+------------------+       +-------------------+
| fw_config hash   |------>| fw_config         |
|                  |       | (Data Image)      |
+------------------+       +-------------------+

Signed-off-by: Louis Mayencourt <louis.mayencourt@arm.com>
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
Change-Id: I08fc8ee95c29a95bb140c807dd06e772474c7367
diff --git a/include/drivers/auth/tbbr_cot_common.h b/include/drivers/auth/tbbr_cot_common.h
index 0ea5f65..a51faee 100644
--- a/include/drivers/auth/tbbr_cot_common.h
+++ b/include/drivers/auth/tbbr_cot_common.h
@@ -10,8 +10,6 @@
 #include <drivers/auth/auth_mod.h>
 
 extern unsigned char tb_fw_hash_buf[HASH_DER_LEN];
-extern unsigned char tb_fw_config_hash_buf[HASH_DER_LEN];
-extern unsigned char hw_config_hash_buf[HASH_DER_LEN];
 extern unsigned char scp_fw_hash_buf[HASH_DER_LEN];
 extern unsigned char nt_world_bl_hash_buf[HASH_DER_LEN];
 
@@ -23,7 +21,7 @@
 
 extern auth_param_type_desc_t tb_fw_hash;
 extern auth_param_type_desc_t tb_fw_config_hash;
-extern auth_param_type_desc_t hw_config_hash;
+extern auth_param_type_desc_t fw_config_hash;
 
 extern const auth_img_desc_t trusted_boot_fw_cert;
 extern const auth_img_desc_t hw_config;