PCI: pci-hyperv: Fix build errors on non-SYSFS config

Fix build errors when building almost-allmodconfig but with SYSFS
not set (not enabled). Fixes these build errors:

ERROR: "pci_destroy_slot" [drivers/pci/controller/pci-hyperv.ko] undefined!
ERROR: "pci_create_slot" [drivers/pci/controller/pci-hyperv.ko] undefined!

drivers/pci/slot.o is only built when SYSFS is enabled, so
pci-hyperv.o has an implicit dependency on SYSFS.
Make that explicit.

Also, depending on X86 && X86_64 is not needed, so just change that
to depend on X86_64.

Fixes: a15f2c08 ("PCI: hv: support reporting serial number as slot information")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Jake Oshins <jakeo@microsoft.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org
Cc: linux-hyperv@vger.kernel.org
Cc: Dexuan Cui <decui@microsoft.com>

drivers/pci/Kconfig

@@ -181,7 +181,7 @@ config PCI_LABEL
 
 config PCI_HYPERV
         tristate "Hyper-V PCI Frontend"
-        depends on X86 && HYPERV && PCI_MSI && PCI_MSI_IRQ_DOMAIN && X86_64
+        depends on X86_64 && HYPERV && PCI_MSI && PCI_MSI_IRQ_DOMAIN && SYSFS
         help
           The PCI device frontend driver allows the kernel to import arbitrary
           PCI devices from a PCI backend to support PCI driver domains.