pnv: Fix reverse dependency on PCI express root ports

qemu-system-ppc64 built with --without-default-devices crashes:

Type 'pnv-phb4-root-port' is missing its parent 'pcie-root-port-base'
Aborted (core dumped)

Have POWERNV to select PCIE_PORT. This is done through a
new PCI_POWERNV config in hw/pci-host/Kconfig since POWERNV
doesn't have a direct dependency on PCI. For this reason,
PCI_EXPRESS and MSI_NONBROKEN are also moved under
PCI_POWERNV.

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <160883058299.253005.342913177952681375.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

hw/pci-host/Kconfig

@@ -60,3 +60,8 @@ config PCI_BONITO
     select PCI
     select UNIMP
     bool
+
+config PCI_POWERNV
+    select PCI_EXPRESS
+    select MSI_NONBROKEN
+    select PCIE_PORT

hw/pci-host/meson.build

@@ -23,7 +23,7 @@ pci_ss.add(when: 'CONFIG_VERSATILE_PCI', if_true: files('versatile.c'))
 
 softmmu_ss.add_all(when: 'CONFIG_PCI', if_true: pci_ss)
 
-specific_ss.add(when: 'CONFIG_POWERNV', if_true: files(
+specific_ss.add(when: 'CONFIG_PCI_POWERNV', if_true: files(
   'pnv_phb3.c',
   'pnv_phb3_msi.c',
   'pnv_phb3_pbcq.c',

hw/ppc/Kconfig

@@ -29,8 +29,7 @@ config POWERNV
     select XICS
     select XIVE
     select FDT_PPC
-    select PCI_EXPRESS
-    select MSI_NONBROKEN
+    select PCI_POWERNV
 
 config PPC405
     bool