block 0 address in the allocator
block 0 address in the allocator

PCI window bars sometimes returns 0 as the a start address. This will
be used by the allocator. Devices or Software can take it as null
address.

Mark 0 address as always allocated during initialization.

Signed-off-by: Nikunj A Dadhania <e2f4a5db9b4735182a88051d1e7a3599f9eac9db@linux.vnet.ibm.com>

qemu/SLOF,aik/SLOF,open-power-host-os/slof,qemu/SLOF,open-power-host-os/slof,stefanberger/SLOF-tpm,qemu/SLOF,agraf/SLOF,agraf/SLOF,agraf/SLOF,aik/SLOF,open-power-host-os/slof,aik/SLOF,agraf/SLOF,stefanberger/SLOF-tpm,open-power-host-os/slof,stefanberger/SLOF-tpm