vga-switcheroo: make PCI dependency explicit

This driver depends on the PCI infrastructure, but the dependency has
not been explicitly called out.

Fixes: 5d32a665 ("PCI/ACPI: Allow ACPI to be built without CONFIG_PCI set")
Signed-off-by: Sinan Kaya <okaya@kernel.org>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/gpu/vga/Kconfig

@@ -21,6 +21,7 @@ config VGA_SWITCHEROO
 	bool "Laptop Hybrid Graphics - GPU switching support"
 	depends on X86
 	depends on ACPI
+	depends on PCI
 	select VGA_ARB
 	help
 	  Many laptops released in 2008/9/10 have two GPUs with a multiplexer