PPC: openpic_kvm: Only map first occurence in address space

PPC: openpic_kvm: Only map first occurence in address space

The in-kernel OpenPIC emulation only supports a single map. However, we
map the OpenPIC at 2 locations: The CPU visible one and the PCI visible
one. For KVM acceleration, we only care about the first one.

To make sure that we only map that first mapping and not the PCI map that
happens dynamically later during bootup, ignore maps that happen when
we are already considering ourselves mapped.

Credits due are to Bogdan and Mihai for debugging this.

Reported-by: Bogdan Purcareata <bogdan.purcareata@freescale.com>
Reported-by: Mihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>