ANDROID: KVM: arm64: Paint the guest IPAs with PAs for FF-A sharing

Copy the guest FF-A buffers into the hypervisor ffa_desc_buf. Validate
the contents of the buffer and paint the addresses of the pages that are
about to be shared from guest with Trustzone into physical addresses.
Store the ipa <-> pa pair in a list which belongs to a transfer and
share the guest pages with FF-A.

Bug: 269285339
Bug: 278749606
Change-Id: Ie3f4b007c40bc1f3242f0832dd4f2948a22387f3
Signed-off-by: Sebastian Ene <sebastianene@google.com>