[Skiboot] [PATCH 2/2] hw/phb3: Ensure PQ bits are cleared in the IVC when masking IRQ

[Vaibhav Jain]

 Tested with genwqe framework to simulate heavy interrupt traffic and cxl
 driver patches at:

 https://github.com/ibm-genwqe/genwqe-user
 http://patchwork.ozlabs.org/patch/613380/
 http://patchwork.ozlabs.org/patch/613381/

 Michael Neuling <mikey at neuling.org> writes:
 > Signed-off-by: Michael Neuling <mikey at neuling.org>
 Tested-by: Vaibhav Jain <vaibhav at linux.vnet.ibm.com>