For randconfig, if a list of required symbols is specified with
KCONFIG_ALLCONFIG, such symbols do not "have a value" as per
sym_has_value(), but have the "valid" flag set.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr> Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>