lguest: now needs PCI_DIRECT.

Since commit 8e709469 ("lguest: add a dummy PCI host bridge.")
lguest uses PCI, but it needs you to frob the ports directly.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/lguest/Kconfig

 config LGUEST
 	tristate "Linux hypervisor example code"
-	depends on X86_32 && EVENTFD && TTY
+	depends on X86_32 && EVENTFD && TTY && PCI_DIRECT
 	select HVC_DRIVER
 	---help---
 	  This is a very simple module which allows you to run