DPE: Allow empty SW_COMPONENTS array

Leaf certificates returned by CertifyKey might not
contain any element in the SW_COMPONENTS array.

Add an empty array to the certificate rather than
omit it. This makes the verification simpler.

Change-Id: I3a1e23e9f9b2d0076402f8d6bfe92097b936258a
Signed-off-by: Tamas Ban <tamas.ban@arm.com>
1 file changed