Documentation: Add host_pnor to Qemu example
Documentation: Add host_pnor to Qemu example

Add --host-pnor to Qemu example in documentation, clarifying that it
is needed for emulating the nvram

Signed-off-by: Klaus Heinrich Kiwi <d568b8cd7ef64877891488bb3328757d2d21c847@linux.vnet.ibm.com>

open-power/op-test-framework,open-power/op-test-framework,open-power/op-test-framework