cactus: remove deprecated hypervisor calls

Hafnium provided VM get count and vcpu get count hypervisor calls which
are now deprecated [1]. The preference is to use FFA_PARTITION_INFO_GET
discovery ABI.

[1] https://git.trustedfirmware.org/hafnium/hafnium.git/
commit/?id=ae3840dbc9372fd407893f32a5d624828c8933ae

Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
Change-Id: Idad95a0804a05d845dc45c2a0f0463f0120d4815
3 files changed