ANDROID: virt: gunyah: Respect nosync reclaims in memextent_donate

This diff was found during testing and is going in future revision of
upstream Gunyah patches. When reclaiming all the VM's memory when
tearing down the virtual machine, we can avoid synchronization and batch
the sync on the last reclaim (see gunyah_vm_reclaim_range()). The flag
was correctly passed to gunyah_hypercall_addrspace_unmap(), but was
missed for the gunyah_hypercall_memextent_donate(). Add it.

Bug: 338347082
Change-Id: I809650b8c6e102a760b6cc589c23aaa18b7bfa2e
Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>