Revert "vm_sockets: Add VMADDR_FLAG_TO_HOST vsock flag"

This reverts commit 29dbdd23 which is
commit caaf95e0 upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: I301f015e5d9692c5d5aebe74923c2a2be206dbd1
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>