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/plat/arm/common/fconf/arm_fconf_io.c b/plat/arm/common/fconf/arm_fconf_io.c
index 68cd9fb..48cc4fe 100644
--- a/plat/arm/common/fconf/arm_fconf_io.c
+++ b/plat/arm/common/fconf/arm_fconf_io.c
@@ -25,6 +25,7 @@
 const io_uuid_spec_t arm_uuid_spec[MAX_NUMBER_IDS] = {
 	[BL2_IMAGE_ID] = {UUID_TRUSTED_BOOT_FIRMWARE_BL2},
 	[TB_FW_CONFIG_ID] = {UUID_TB_FW_CONFIG},
+	[FW_CONFIG_ID] = {UUID_FW_CONFIG},
 #if !ARM_IO_IN_DTB
 	[SCP_BL2_IMAGE_ID] = {UUID_SCP_FIRMWARE_SCP_BL2},
 	[BL31_IMAGE_ID] = {UUID_EL3_RUNTIME_FIRMWARE_BL31},
@@ -73,6 +74,11 @@
 		(uintptr_t)&arm_uuid_spec[TB_FW_CONFIG_ID],
 		open_fip
 	},
+	[FW_CONFIG_ID] = {
+		&fip_dev_handle,
+		(uintptr_t)&arm_uuid_spec[FW_CONFIG_ID],
+		open_fip
+	},
 #if !ARM_IO_IN_DTB
 	[SCP_BL2_IMAGE_ID] = {
 		&fip_dev_handle,