feat(spm): build only spmc/hyp targets

Leverage new build option to Hafnium project to specify
a list of targets, to build SPM and Hypervisor only
for FVP platform.

Signed-off-by: J-Alves <joao.alves@arm.com>
Change-Id: I715af7d72454459af4103fcf306c382ae6695ae0
diff --git a/spm_config/fvp-spm-hyp b/spm_config/fvp-spm-hyp
index 7d8d20b..0190179 100644
--- a/spm_config/fvp-spm-hyp
+++ b/spm_config/fvp-spm-hyp
@@ -1 +1,2 @@
 PROJECT=reference
+PLATFORM=secure_aem_v8a_fvp_vhe,aem_v8a_fvp_vhe