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
1 file changed