Revert "build: config: allow bool to select a module pkg"

This reverts commit 8514b6b4.

Reverting this commit in preparation for reverting
dcf3e63a ("build: scripts/config - update to kconfig-v5.6") which
introduces various unaddressed build breakages.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>