kconfig: add an option to determine a menu's visibility

This option is aimed to add the possibility to control a menu's visibility
without adding dependency to the expression to all the submenu.

Signed-off-by: Arnaud Lacombe <lacombar@gmail.com>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Tested-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/scripts/kconfig/zconf.gperf b/scripts/kconfig/zconf.gperf
index d8bc742..c9e690e 100644
--- a/scripts/kconfig/zconf.gperf
+++ b/scripts/kconfig/zconf.gperf
@@ -38,6 +38,7 @@
 string,		T_TYPE,		TF_COMMAND, S_STRING
 select,		T_SELECT,	TF_COMMAND
 range,		T_RANGE,	TF_COMMAND
+visible,	T_VISIBLE,	TF_COMMAND
 option,		T_OPTION,	TF_COMMAND
 on,		T_ON,		TF_PARAM
 modules,	T_OPT_MODULES,	TF_OPTION