PCI: drivers/pci/slot.c should depend on CONFIG_SYSFS

There is no way to interact with a physical PCI slot without
sysfs, so encode the dependency and prevent this build error:

	drivers/pci/slot.c: In function 'pci_hp_create_module_link':
	drivers/pci/slot.c:327: error: 'module_kset' undeclared

This patch _should_ make pci-sysfs.o depend on CONFIG_SYSFS too,
but we cannot (yet) because the PCI core merrily assumes the
existence of sysfs:

	drivers/built-in.o: In function `pci_bus_add_device':
	drivers/pci/bus.c:89: undefined reference to `pci_create_sysfs_dev_files'
	drivers/built-in.o: In function `pci_stop_dev':
	drivers/pci/remove.c:24: undefined reference to `pci_remove_sysfs_dev_files'

So do the minimal bit for now and figure out how to untangle it
later.
Reported-by: NRandy Dunlap <randy.dunlap@oracle.com>
Acked-by: NRandy Dunlap <randy.dunlap@oracle.com>
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Fix-suggested-by: NMatthew Wilcox <matthew@wil.cx>
Signed-off-by: NAlex Chiang <achiang@hp.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

drivers/acpi/Kconfig

@@ -266,6 +266,7 @@ config ACPI_DEBUG_FUNC_TRACE
 
 config ACPI_PCI_SLOT
 	tristate "PCI slot detection driver"
+	depends on SYSFS
 	default n
 	help
 	  This driver creates entries in /sys/bus/pci/slots/ for all PCI

drivers/pci/Makefile

@@ -2,10 +2,11 @@
 # Makefile for the PCI bus specific drivers.
 #
 
-obj-y		+= access.o bus.o probe.o remove.o pci.o quirks.o slot.o \
+obj-y		+= access.o bus.o probe.o remove.o pci.o quirks.o \
 			pci-driver.o search.o pci-sysfs.o rom.o setup-res.o \
 			irq.o
 obj-$(CONFIG_PROC_FS) += proc.o
+obj-$(CONFIG_SYSFS) += slot.o
 
 # Build PCI Express stuff if needed
 obj-$(CONFIG_PCIEPORTBUS) += pcie/

drivers/pci/hotplug/Kconfig

@@ -4,7 +4,7 @@
 
 menuconfig HOTPLUG_PCI
 	tristate "Support for PCI Hotplug"
-	depends on PCI && HOTPLUG
+	depends on PCI && HOTPLUG && SYSFS
 	---help---
 	  Say Y here if you have a motherboard with a PCI Hotplug controller.
 	  This allows you to add and remove PCI cards while the machine is