cert_create: add SiP owned secure partitions support

Add support to generate certificate "sip-sp-cert" for Secure
Partitions(SP) owned by Silicon provider(SiP).
To avoid deviation from TBBR specification the support is only added for
dualroot CoT and not for TBBR CoT.

A single certificate file is generated containing hash of individual
packages. Maximum 8 secure partitions are supported.

Following new options added to cert_tool:
 --sip-sp-cert --> SiP owned Secure Partition Content Certificate
 --sp-pkg1 --> Secure Partition Package1 file
 --sp-pkg2
 .....
 --sp-pkg8

Trusted world key pair is used for signing.

Going forward, this feature can be extended for Platfrom owned
Partitions, if required.

Signed-off-by: Manish Pandey <manish.pandey2@arm.com>
Change-Id: Ia6dfbc1447cfb41b1fcbd12cf2bf7b88f409bd8d
diff --git a/make_helpers/tbbr/tbbr_tools.mk b/make_helpers/tbbr/tbbr_tools.mk
index f0adfe1..9520934 100644
--- a/make_helpers/tbbr/tbbr_tools.mk
+++ b/make_helpers/tbbr/tbbr_tools.mk
@@ -99,3 +99,8 @@
     $(eval $(call TOOL_ADD_PAYLOAD,${BUILD_PLAT}/nt_fw_key.crt,--nt-fw-key-cert))
 endif
 endif
+
+# Add SiP owned Secure Partitions CoT (image cert)
+ifneq (${SP_LAYOUT_FILE},)
+    $(eval $(call TOOL_ADD_PAYLOAD,${BUILD_PLAT}/sip_sp_content.crt,--sip-sp-cert))
+endif