cactus: re-align secure partition id

According to [1] and [2] secure partition ids are defined from
0x8001 to 0xfffe. Update the cactus test payload and TFTF such
that it uses the appropriate IDs.
0x8000 and 0xffff are reserved FF-A IDs respectively for the SPMC
and the SPMD.
Conversely in the NWd, the Hypervisor ID is 0 and VMs are numbered
in the range of 1 to 0x7fff.

[1] https://trustedfirmware-a.readthedocs.io/en/latest/components/
secure-partition-manager.html#ffa-id-get
[2] https://review.trustedfirmware.org/c/hafnium/hafnium/+/5165

Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
Change-Id: I3e9786212b227e6637a7650e60ddc4e59ad05a46
6 files changed