(ghost/spec) `pkvm_host_map_guest` only copying the pkvm state when n…

…eeded

when no memcache donation happened during the hcall, the pkvm lock
will not have been taken (and therefore there is nothing to copy).

init ghost_control dynamically

All pKVM core patches destined for upstream and based on Linux 6.4

KVM: arm64: kcov: Add kcov support in EL2 object

Change-Id: Ib1556c1194a0bae23438746bd3175ac780fae727