phb4: Enable PHB MMIO-0/1 Bars only when mmio window exists
phb4: Enable PHB MMIO-0/1 Bars only when mmio window exists

Presently phb4_probe_stack() will always enable PHB MMIO0/1 windows
even if they doesn't exist in phy_map. Hence we do some minor shuffling
in the phb4_probe_stack() so that MMIO-0/1 Bars are only enabled if
there corresponding MMIO window exists in the phy_map. In case phy_map
for an mmio window is '0' we set the corresponding BAR register to
'0'.

Signed-off-by: Vaibhav Jain <e78384dfaa97bf0f3945c4da4075af8ac33ade0a@linux.ibm.com>
Reviewed-by: Oliver O'Halloran <3dfaff8fa6ae977f042064a112a6aac576279b9b@gmail.com>
Signed-off-by: Stewart Smith <ec31ab75ddf977353c8f660f92ea8b23f64aef25@linux.ibm.com>

qemu/skiboot,legoater/skiboot,open-power/skiboot,open-power/skiboot,open-power/skiboot,stewart-ibm/skiboot,stewart-ibm/skiboot,shenki/skiboot,shenki/skiboot,qemu/skiboot,qemu/skiboot,legoater/skiboot,legoater/skiboot,legoater/skiboot,shenki/skiboot,stewart-ibm/skiboot,open-power/skiboot,shenki/skiboot,shenki/skiboot,qemu/skiboot,legoater/skiboot,qemu/skiboot,open-power/skiboot