Upcoming in-kernel VFIO acceleration needs different handling in real
and virtual modes which makes it hard to support both modes in
the same handler.

This creates a copy of kvmppc_rm_h_stuff_tce and kvmppc_rm_h_put_tce
in addition to the existing kvmppc_rm_h_put_tce_indirect.

This also fixes linker breakage when only PR KVM was selected (leaving
HV KVM off): the kvmppc_h_put_tce/kvmppc_h_stuff_tce functions
would not compile at all and the linked would fail.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>