gpu: nova-core: gsp: add tests for continuation records

gpu: nova-core: gsp: add tests for continuation records

Add tests for continuation record splitting. They cover boundary
conditions at the split points to make sure the right number of
continuation records are made. They also check that the data
concatenated is correct.

Tested-by: Zhi Wang <zhiw@nvidia.com>
Signed-off-by: Eliot Courtney <ecourtney@nvidia.com>
Link: https://patch.msgid.link/20260306-cmdq-continuation-v6-9-cc7b629200ee@nvidia.com
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>