TF-M CI: Support Isolation Level 3

TF-M has added Isolation Level 3 as a new feature.
Isolation Level 3 could only be supported by AN521 and MUSCA_B1.
CI needs to support this new feature.

Change-Id: I8619753fde9bf7804a7b7f7d76b63af1949af6b7
Signed-off-by: Xinyu Zhang <xinyu.zhang@arm.com>
1 file changed