Pass an FDT to the unit test VMs

Instead of passing the assigned memory size, optionally pass the
FDT to the secondary VMs. The VMs can extract the memory size, as
well as other potentially useful information from the FDT.

This is done to facilitate using the same unit test framework
with kvm-unit-tests, which expects an FDT, as does the Linux
kernel.

Change-Id: I436d86b3f4d1540c1995e01e48289f39e2c23490
Signed-off-by: Fuad Tabba <tabba@google.com>
diff --git a/inc/hf/manifest.h b/inc/hf/manifest.h
index a5ce7cb..9e571b1 100644
--- a/inc/hf/manifest.h
+++ b/inc/hf/manifest.h
@@ -134,6 +134,7 @@
 		struct {
 			uint64_t mem_size;
 			ffa_vcpu_count_t vcpu_count;
+			struct string fdt_filename;
 		} secondary;
 	};
 };