build: config: allow bool to select a module pkg

build: config: allow bool to select a module pkg

kconfig-v5.6 disallowed a bool symbol to select another symbol that
'depends on m' (i.e. can be only 'm' on 'n').  It is, in fact, an unmet
dependency to have set to 'y'.  However, openwrt depends on the previous
behavior, to be able to build a package that can be a module or built-in
depending on a bool config.  This restores the previous behavior.

Ref: https://forum.openwrt.org/t/wireless-fails-on-snapshot-r12900-kernel-5-4-on-c2600-ipq806x
Tested-by: Hannu Nyman <hannu.nyman@iki.fi>
Signed-off-by: Eneas U de Queiroz <cotequeiroz@gmail.com>
Signed-off-by: Petr Štetiar <ynezz@true.cz> [added forum ref]