PCI: only build xen-pcifront in PV-enabled environments

The driver's module init function, pcifront_init(), invokes
xen_pv_domain() first thing. That construct produces constant "false"
when !CONFIG_XEN_PV. Hence there's no point building the driver in
non-PV configurations.

Drop the (now implicit and generally wrong) X86 dependency: At present,
XEN_PV can only be set when X86 is also enabled. In general an
architecture supporting Xen PV (and PCI) would want to have this driver
built.

Signed-off-by: Jan Beulich <[email protected]>
Reviewed-by: Stefano Stabellini <[email protected]>
Acked-by: Bjorn Helgaas <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Juergen Gross <[email protected]>

Author: jbeulich

drivers/pci/Kconfig

@@ -110,7 +110,7 @@ config PCI_PF_STUB
 
 config XEN_PCIDEV_FRONTEND
 	tristate "Xen PCI Frontend"
-	depends on X86 && XEN
+	depends on XEN_PV
 	select PCI_XEN
 	select XEN_XENBUS_FRONTEND
 	default y