DPE: Store number of components in a layer

When creating certificate, layer index is being checked against to
identify if a component belongs to that layer. Instead add extra
attribute which stores the components when added to the layer.
This reduces dependency between context manager and certificate/crypto
functions.

Signed-off-by: Maulik Patel <maulik.patel@arm.com>
Change-Id: I78ad80535cd6e77f8fffaf99b5983ca6c08dc2c4
3 files changed