um: Wire CONFIG_GENERIC_IO up

UML has no io memory but implements everything defined in
generic-asm/io.h.

Signed-off-by: Richard Weinberger <richard@nod.at>
diff --git a/arch/um/Kconfig.common b/arch/um/Kconfig.common
index b37ae70..20a49ba 100644
--- a/arch/um/Kconfig.common
+++ b/arch/um/Kconfig.common
@@ -9,6 +9,7 @@
 	select HAVE_GENERIC_HARDIRQS
 	select GENERIC_IRQ_SHOW
 	select GENERIC_CPU_DEVICES
+	select GENERIC_IO
 
 config MMU
 	bool