DPE: Fix leaf component derivation test

Using DeriveChild command, derive a context,
setting it as a leaf (allow_new_context_to_derive = false).
Try to derive new context from the same context and
check if it fails.

Signed-off-by: Maulik Patel <maulik.patel@arm.com>
Change-Id: Ibd543376a74f9cb7b641896ddec49d4f40390dcb
1 file changed