spm-mm: decouple smp-mm tests from spm tests

As spm and spm-mm tests are not logically related its better to
decouple them. This patch moves all spm-mm tests to a separate
"tf-l3-boot-tests-spm-mm" group.

Change-Id: I8b20b073afeb0df1eca4832a74b683b992b19487
Signed-off-by: Manish Pandey <manish.pandey2@arm.com>
7 files changed