ANDROID: KVM: arm64: Introduce hyp_alloc_account for the pKVM hyp

Add a new interface for the pKVM hyp heap allocator, hyp_alloc_account()
and hyp_free_account(). When used the memory allocated and freed is
accounted against a host shared counter protected_hyp_mem.

This intends to later report detailed memory footprint of the hypervisor
to the host.

Bug: 278749606
Bug: 222044477
Change-Id: I76bc8a2a5e4fb59bf5fd40aa666d2467b6faeb17
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>