ANDROID: Revert "KVM: arm64: Expose topup_hyp_memcache() to the rest of KVM"

The upcoming hypervisor heap allocator will use hyp_memcache to carry
over memory from host to hyp and vice versa. We then need a topup
function which can handle any mc, not only the VCPUs.

This reverts commit 817c8dcb5d05131cdfa8e0a6eff611bbe65fc568.

Bug: 278749606
Bug: 273748186
Change-Id: Id55e45ab52a99fed16a2862509b302d696e322af
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>