KVM: arm64: Add flags to kvm_hyp_memcache

Add flags to kvm_hyp_memcache and propagate the latter to the allocation
and free callbacks. This will later allow to account for memory, based
on the memcache configuration.

Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250313114038.1502357-2-vdonnefort@google.com


Signed-off-by: Oliver Upton <oliver.upton@linux.dev>