vga: compile fix, disable vga for s390

Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

drivers/gpu/vga/Kconfig

@@ -1,7 +1,7 @@
 config VGA_ARB
 	bool "VGA Arbitration" if EXPERT
 	default y
-	depends on PCI
+	depends on (PCI && !S390)
 	help
 	  Some "legacy" VGA devices implemented on PCI typically have the same
 	  hard-decoded addresses as they did on ISA. When multiple PCI devices