fvp: add support for Secure Partitions in the FIP

This commit introduces a new packaging option for Secure Partitions.
Instead of embedding the images into the OP-TEE binary, TF-A offers a
mechanism to encapsulate an SP image and its manifest into an SP package
and add that to the FIP [1].

TF-A needs two config options to enable this:
 - SP_LAYOUT_FILE: This json file contains the path of the SP images and
   their corresponding manifests. It's generated by Trusted Services.
 - ARM_BL2_SP_LIST_DTS: This dts snippet describes where each SP package
   should be loaded by BL2.

Link: [1] https://trustedfirmware-a.readthedocs.io/en/v2.6/components/secure-partition-manager.html#secure-partition-packages
Acked-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Balint Dobszay <balint.dobszay@arm.com>
diff --git a/fvp-psa-sp.mk b/fvp-psa-sp.mk
index 66eb76d..5e10ba8 100644
--- a/fvp-psa-sp.mk
+++ b/fvp-psa-sp.mk
@@ -5,6 +5,7 @@
 MEASURED_BOOT_FTPM		?= n
 TS_SMM_GATEWAY			?= y
 TS_UEFI_TESTS			?= y
+SP_PACKAGING_METHOD		?= embedded # Supported values: embedded, fip
 
 TF_A_FLAGS ?= \
 	BL32=$(OPTEE_OS_PAGER_V2_BIN) \
@@ -12,7 +13,8 @@
 	PLAT=fvp \
 	SPD=spmd \
 	SPMD_SPM_AT_SEL2=0 \
-	ARM_SPMC_MANIFEST_DTS=$(ROOT)/build/fvp/spmc_manifest.dts
+	ARM_SPMC_MANIFEST_DTS=$(ROOT)/build/fvp/spmc_manifest.dts \
+	$(TF_A_FIP_SP_FLAGS)
 
 include fvp.mk
 include trusted-services.mk